drop in the Cadillac with a body style of 80's Fleetwood and Brougham rear wheel drive? Those cars are dime a dozen, but we all heard stories about HTs and 8-6-4, well, that alone probably deserves a separate section in the forum LOL.

Would anyone tell me?

P.S. Admin, if this question was asked before and there is no doubt in my mind that it has, kindly direct me to that thread via PM and feel free to either lock or delete this thread altogether. No need to waste threads. :thumbsup:

So far, and hopefully Katshot agrees, the LT1/4L60E from 94-96 was one of the least troubling drivetrains GM has ever had. The 3800 is quite impressive too, but I don't think you want 170 hp/225 lb/ft torque to move a Cad....

Maybe turbocharged....

Yeah, I'd have to agree on the LT1 too. Pretty easy to find (LOTS of wrecked Camaro's, Trans Ams, etc.), one of the more recent and excellent GM small block V8's, plus from what I've read, is MUCH less difficult to transplant in a non-original vehicle than something newer like an LT1 is, because of the electronics.

Then again, compared to most of the garbage engines they put in the 80's Fleetwoods/Broughams, virtually ANY fuel injected 350 V8 from the 90's+ would be a great choice. Case in point, I have an undying love for the L05 5.7L V8 in my '93 FWB, even if it can't do as much of a burn out as a LT1 car might be able to--it still has MAJOR balls, can shock a lot of people off the line, and is turbine smooth and silent throughout the entire RPM range. LOVE IT! I guess I just might die if I got to drive an LT1 car, already having feelings like this!

RELIABLE engine?

the Olds 307 used from 1985-1989

and it is an easy swap... they are already in there :)

if you mean to swap in to an HT car.... then, well, if you only wanted the most reliable enigne, I would say the 307... but if you wanted some snap, I would say a Cad 472/500..... if you wanted to keep something called gas mileage then a Chevy 350 would work

280hp/320ft-lbs torque from a s/c Series II 3800 with smaller s/c pully (only mod) dosn't sound bad to me.... not that it would be an easy or practical swap tho.

The 307 that comes stock in the 80's cadilacs is about as reliable as you can get short of cutting huge holes in your floor and pulling a Flinstones manuver.
if the 307 isnt too reliable seeming, it may be because its high milelage, improperly maintained, or everything around it is broken.
of course, that isnt much of an answer to your question...But of course theres the option of the 350 chevy..but at that point it might be easier to just buy a brougham from 1990-1992 when they became a standard option.
Mabey the drive system from one of them tunnel of love swan boats? Nevermind, that only works if your Lance Armstrong.

-Eric

I agree with the 307. Some people feel it's sluggish but in my opinion if you keep it well tuned it performs all right. I think it would be a perfect alternative to an HT4100 if you wanted to steer clear of the big boy Caddy engines of the 70's. I almost came into posession of an 83 Coupe de Ville as a project car that if I swapped the engine, I'd put a 307 in it. You just can't kill that engine.

Personally I'd go with a 350 TBI, 350 Vortec, or LT-1. The fuel injection and computer makes the reliability even better, nicer starts in the winter, better mileage, and so on.

Personally I'd go with a 350 TBI, 350 Vortec, or LT-1. The fuel injection and computer makes the reliability even better, nicer starts in the winter, better mileage, and so on.

Yeah, that's the BIG point here. There's just NO way I'd want an old carbed V8 in one of these cars, especially not one as new as the late 80's. By that time, I never did get why relatively sluggish V8's lacking fuel injection were STILL being used.

Also, for me, the whole reliability factor is probably the biggest. If it were a once a month cruise & show car, I wouldn't mind having to do some work to get it started. But as a daily, or semi-daily driven car, the carb certainly wouldn't be as trouble-free reliable and efficient as fuel injection would.

... but if you wanted some snap...

Actually, I could care less about snap. These are not sports cars. I just want reliability.;) And thanks for replies everybody.

Since the engine itself is not the only factor for reliability it depends on which year you are starting off with and how good a job at automotive re-wiring can be done. I love run on sentences.

in 1980 they did have the carbed 368, which I *assume* is a good engine as engines go. Reading the forums I can see few complaints with it.

I've found two where I live, one a coupe deville and the other a fleetwood brougham two door. According to internet sources the fleetwood is rarer but both cars are essentially the same to my understanding.

My problem is, where does the car buying end for me? I can't take care all of them, as it is having four cars insured is tough enough. But I so do want the fleetwood, right colour, mileage and needs some haggling on the price.

So why post? I need some peer pressure to fend off logic...

Buy, buy, buy. :p

Get something you can have classic car insurance on, since it's hella cheap.

well spock...its a 2 dr. rare...good condition...old big block caddy power and if u like ur 86 i bet u will love the extra HP and torque of the 368, and a real plus the car is ALL caddy...not a little buick or olds or chevy...all caddy all the time. that would be a great car to swap a 472 or 500 in also....probably swap the motor mounts and be done.

This is REALLY a tough question. I have to agree with a lot of you for several reasons. The 368 that came in the early 80's was a great engine. The V-8-6-4 system gave the 368 a black-eye that it didn't deserve. If you use one of these engines, you'll have an easy install and good reliability. They weren't the strongest engine and didn't get great MPG but they were reasonable in both departments IMO.
The Olds 307 was absolutely one of the most rock-solid reliable engines around but they were rather under-powered, and even though you say you don't care about "snap", it "may" get a little old after a while.
The Chevy 350's.......what can I say, IMO, all are great engines. The LO5 from the truck division is a solid engine but not terribly powerful. I'd say it will probably out-perform the 368 alright but, the LT1 has reliability, power, AND great gas mileage! A combination that's hard to beat these days considering gas isn't getting any cheaper.
The engines I mentioned are not only in order of availability from the OEM (chronologically speaking) but also in order of complexity of install.
In the end, any of these engines won't let you down. It'll probably boil down to cost, availability and your desire for an easy swap or a big project.

I know everyone raves about the reliability of the Olds 307 and yes the cars this motor came were reliable but is that the whole story?. Dont forget most of the cars that had this motor also had very high gears (2:21? or so). Then with the Chevy powered models they went to a 3.08 and I know there are some out there with 3.42's. What I'm getting at is that the 307 is reliable but nobody ever really asked much of it. Put a 3.08 gear or 3.42 behind a 307 and reliability would suffer. In addition the 307 is a real sluggish motor with 140hp. Almost any motor would be reliable under the conditions of the 307. Nobody beats on it because there is no reward for it, its geared so that it really does not have to work that hard. If someone drove a 307 like an LT1, the LT1 or any other sbc would come out ahead IMO.

Olds 307 cars had 2.56 gears.... IIRC somewhere around there.

my '79 DeVille has 2.28 gears, so it has even worse gearing for performance.

Also, the Olds 307 was bolted t the 200R4 (or was it the 700R4? I think the 200....) either way, yeah, it has over drive, but honstly, it is a junk transmission... stock atleast, both my mother and her finacee had to get a trans rebuild around 120-150k miles in their Broughams ('87/'89) on the same note, the Turbo400 would go on and on and on never, ever giving you any problems.

Also.... whats the big deal with a carburator? I personally like a carburator more then a complex fuel injection system, thats just me though.... hard starting? it really isn't all that hard to pump the gas twice and turn the key.... the only real draw back would be winter starting... which for me isn't an issue because the '79 dosn't get used in the winter... actually now that I live in FL, my winters are not like NY winters :) but even then, the few times I did use the '79 in the winter, pump the gas twice, turn it over for 3 seconds, stop, pump the gas twice more and then she fires right up.... simple process, after only 3 or 4 minutes it was warmed up enough to the point that it wouldn't stall..... hardly an inconvience. My mothers Brougham was the same way, now if you factor in most people let the car warm up to heat the car, or run the engine while they clear snow off it, it isn't a big deal.

Really, I don't know what the big fuss over a carburator is.... I like em'

the Olds 307.... well, the good thing is, it is more powerful then the HT4100, that was just a joke in the big bodys... but you gotta make sure there is a large gap in traffic to merge, gaining speed up a hill dosn't happen.... the car is just slow. My mother floors it at times to get up to speed..... my mother. When she rented an '05 Nissan Sentra with the 1.8L 4banger and auto, she kept saying how much power the car had and how quick it got up to speed and stuff.... I'll admit, I drove that car and it wasn't bad for what it was.... but comeon, when a cheap econo car has that much more of a difference in power then the Caddy.... that is just sad.

Another vote for the LT1 considering the fuel injection, quick and easy power, wide availability, reliability, gas mileage, etc.
Another thing to mention is that the optispark distributor on the LT1 engines have a bad reputation, generally considered about a 100K mile part. But in reality, if you put it in perspective, what other distributor can you allow to go unserviced for 100K miles?
To me the opti is a decent upgrade over traditional distributor systems, GM just put it in a bad location.

Also to note, the taxi cabs and police vehicles used the LT1 powered Caprices for well over 100K miles and trusted them.
Before the LT1 cars, the L03 (5.0 liter) and L05 (5.7 liter) were the engines that powered Caprices. Reliable as well, but not sure they can compare in gas mileage vs. power available.

Happy motoring

I know everyone raves about the reliability of the Olds 307 and yes the cars this motor came were reliable but is that the whole story?. Dont forget most of the cars that had this motor also had very high gears (2:21? or so). Then with the Chevy powered models they went to a 3.08 and I know there are some out there with 3.42's. What I'm getting at is that the 307 is reliable but nobody ever really asked much of it. Put a 3.08 gear or 3.42 behind a 307 and reliability would suffer. In addition the 307 is a real sluggish motor with 140hp. Almost any motor would be reliable under the conditions of the 307. Nobody beats on it because there is no reward for it, its geared so that it really does not have to work that hard. If someone drove a 307 like an LT1, the LT1 or any other sbc would come out ahead IMO.

I have a few problems with this post.
Based on your stated theory I would assume that the HT4100 would've been VERY reliable since it only had 130HP. Or how about the Olds 350 Diesel with 120HP. No, sorry, just because something has a low horsepower rating, that doesn't mean it's going to be reliable.
And about those horsepower ratings....you have to remember that back then, cars didn't have the kind of horsepower that you see these days. As an example, take a look at the Cadillac lineup of 1988:
4.1 liter (Allante only) - 170hp/ 235lb/ft torque@3200rpm
4.5 liter (all other FWD car except Cimarron) - 155hp/ 240lb/ft torque@2800rpm
5.0 liter (307Y in RWD cars) - 140hp/ 255lb/ft torque@2000rpm
Notice it was NOT under-powered as compared to the rest of the line up. Horsepower was a little low but torque was the highest of the whole line up and that was from a mere 2000rpm! My guess is the tall gears were used on the RWd cars w/307 engines because the engine had the torque to use them.
The other thing I need to point out is that your comment about how tall gears (low numerically) are easier on the engine is actually backwards. The final drive ratio of any drivetrain determines to a great degree, the mechanical load placed on the engine and transmission. The mechanical advantage of short gears is very simple to prove. You ever try to climb a hill on a 10-speed in tenth gear? Very hard isn't it? So actually your point about gearing actually serves to show even more that the 307 (Y) was a solid engine.

Before the LT1 cars, the L03 (5.0 liter) and L05 (5.7 liter) were the engines that powered Caprices. Reliable as well, but not sure they can compare in gas mileage vs. power available.

Happy motoring


The power output of an LO5 or a Vortec 350 is not quite that of an LT-1. The torque output is relatively simliar, however, the LT-1 has 260 horsepower (please correct if wrong) meaning she's making usable torque higher into the RPM band. All 3 are very very reliable engines, and all 3, with the L05 leading because of being generation 1 SBC, have large aftermarket possibilities. As for mileage, all three are also going to be similar, but mileage has a lot more to do with your personal driving habits than subtle differences between 3 closely related SBC's.

I have a few problems with this post.
Based on your stated theory I would assume that the HT4100 would've been VERY reliable since it only had 130HP. Or how about the Olds 350 Diesel with 120HP. No, sorry, just because something has a low horsepower rating, that doesn't mean it's going to be reliable.
And about those horsepower ratings....you have to remember that back then, cars didn't have the kind of horsepower that you see these days. As an example, take a look at the Cadillac lineup of 1988:
4.1 liter (Allante only) - 170hp/ 235lb/ft torque@3200rpm
4.5 liter (all other FWD car except Cimarron) - 155hp/ 240lb/ft torque@2800rpm
5.0 liter (307Y in RWD cars) - 140hp/ 255lb/ft torque@2000rpm
Notice it was NOT under-powered as compared to the rest of the line up. Horsepower was a little low but torque was the highest of the whole line up and that was from a mere 2000rpm! My guess is the tall gears were used on the RWd cars w/307 engines because the engine had the torque to use them.

I dont have a "theory" just common sense. I had an 87 FWB w/307, a 4.1 87 Deville, 305 and 350 sbc FWB. I'm not saying that a weak motor is a more reliable motor. I'm saying that the 307 was simply not meant to do much. So if I drive an LT1 FWB and I get on it a lot and I accumulate 120k before it needs a rebuild and your 307 makes it to 170k till it needs a rebuild, would your motor be in fact more reliable?. Which motor worked more through its lifespan, the weak one or the powerful one?.What if I took that LT1, lowered the compression, lowered the power to 140hp and intalled 2.56 gears in it. Do you think it would make it to 170k miles then? I do.



"The other thing I need to point out is that your comment about how tall gears (low numerically) are easier on the engine is actually backwards. The final drive ratio of any drivetrain determines to a great degree, the mechanical load placed on the engine and transmission. The mechanical advantage of short gears is very simple to prove. You ever try to climb a hill on a 10-speed in tenth gear? Very hard isn't it? So actually your point about gearing actually serves to show even more that the 307 (Y) was a solid engine."





Listen man, are you recommending that we all install 4.56 gears in our cars to improve reliability?. That argument about climbing a hill in tenth gear on a 10 speed is weak. I'm talking about daily driving and cruising at speed which is what these cars are used for. I dont know what mountain you are climbing with your car but a 307 going uphill, well.........probably wouldn't make it up that hill. A taller gear will rev lower at speed than a shorter gear, agreed?.

No, he's talking about mechanical advantage. It's essentially like using different sized ractched to turn a bolt. 2.42 gears are like using a shorty 1/4th drive ratchet. 5.11 gears are like using an inch drive 5-foot flex handle. The 5-foot flex handle will do the job much easier, but it has to travel a longer distance (the engine spooling out higher). The shorty ratchet doesn't have to travel as far but it has to work much harder.

Brian gets it. I'm talking about "all things being equal" the taller gears are actually harder on the engine and trans because they give less mechanical advantage to do the same amount of work.
You seem to be trying to say that the more powerful engine will be driven harder by it's driver, so it will not last as long. That's comparing apples to oranges.
There IS another side to your arguement though. What about the idea that the weaker engine will spend a lot more time at higher loads TRYING to pull that car around at a pace that might please the "average" owner, while the more powerful engine will probably manage the needs of the "average" owner more easily. I know that if I have a car with a wimpy engine, I'm on it hard all the time trying to get around, whereas in a more powerful car, a lighter touch on the gas is usually enough to get around just fine.
Are you getting the idea now?
I'm not sure I can explain it any simpler.

While overall power output of the 307 was generally in line with the rest of the line up at the time... keep in mind the RWD cars weighed a good 1,000lbs more and...the gearing... all help to make the car feel slower.

and actually, a lower power engine has to work harder then a high power engine to move a similar car around.... so in essance, the 307 is working alot harder then a 350... why? because you would be running the 307 wide open all the time just to get moving, where compared to the 350 you may only be using 2/3 throttle.... just because the engine does make the car fast enough to pin you in the seat dosn't mean it is not working hard.

kinda like how the 425 in my '79 DeVille, even with the 2.28 gears, dosn't seem to work all that hard to get the car moving fast, never goes above 2,000RPM's unless I have the secondaries open... that is only 180hp.... now if you get a Honda 4 cylinder with 180hp... hell, more then 180hp and magically put that in the '79 DeVille... you'd be lucky if it would even start to move the car.

As much as I say about the 307, really, for what it is, was put into, and expected to do, it does a fine job. the 255ft-lbs of torque are what saves it. It gets rather good fuel mileage for the year and size of the car... 15mpg town and 24mpg highway? not too bad. It hardly requires any maintenace, is smooth and quiet, and for the old people that bought the car (which is who it was marketed to) it was powerful enough. Those cars were not made to go fast, and honestly on the highway with the cruise set at 75mph, it wouldn't make a difference if you had 140hp or 260hp, if the car is maintaining the speed, then its fine.

Brian gets it. I'm talking about "all things being equal" the taller gears are actually harder on the engine and trans because they give less mechanical advantage to do the same amount of work.
You seem to be trying to say that the more powerful engine will be driven harder by it's driver, so it will not last as long. That's comparing apples to oranges.
There IS another side to your arguement though. What about the idea that the weaker engine will spend a lot more time at higher loads TRYING to pull that car around at a pace that might please the "average" owner, while the more powerful engine will probably manage the needs of the "average" owner more easily. I know that if I have a car with a wimpy engine, I'm on it hard all the time trying to get around, whereas in a more powerful car, a lighter touch on the gas is usually enough to get around just fine.
Are you getting the idea now?
I'm not sure I can explain it any simpler.No!. An engine that has to live with more rpm's its ENTIRE life is worked harder than an engine that has struggle to pull up a hill SOME of its life. Look, I've owned several 307 powered cars inluding an 85 Buick Lesabre, '88 Olds Cutlass and an 87 Cadillac, I know the motor well. I never had any issues with the 307, it was a reliable powerplant as was the slant 6 in my 68 Dart convertible. All I am saying is that it really does not lead a hard life as compared to the countless cop cars and cabs running a motor like the LT1. An LT1 with "X" amount of miles is more impressive than a 307 with "X+" miles. A motor with a higher numerical gear DOES work harder through its life, nothing you or anyone says will tell me otherwise. The 307 may struggle to get up a hill but its still doing it in the lower rpm range. No hardcore vechicle like a cop car or cab had ever used a 307, it would never cut it for anything more than old geezer usage. The 80's Fleetwoods should have at least utilized the TPI 305's or 350's, it was afterall the top model in the Cadillac lineup. The motors were there, they should have been utilized. GM's cost cutting crap also put the truck TBI motors in Caddy's when they should have been using the TPI Vette 5.7's.

I have owned L98's, LT1's, Olds 307's 330's 350's 400's 455's, I KNOW OLDS motors!. I know that an Impala SS owner will drive his car harder than the owner of a 307 Olds car, period. When seeking the most "reliable" motor, lets take all things into consideration. :alchi:

I have to disagree with lower RPM = more easy engine life.

If you have a manual transmisson, and say put it in 5th gear at 30mph, then floor it... not only will it accelerate very slow, but that causes ALOT of internal engine wear.... you are lugging the engine, I am not saying drive around at redline all day, but say with a manual transmission if it came between being at too high of an RPM or too low of an RPM... the best bet would be too high of an RPM, the only thing it is doing at that point would be wasting gas... but lugging the engine at too low of an RPM it has to strain just to maintain that speed, cause lots of intenral stress.

lower gearing (higher number) is more easy on the engine though, I can see what you mean by saying it'll be at a higher RPM, but I am talking within reason... obviously not turning over a 307 over at 4,000RPM on the highway, but the lower gearing will alow the engine to not have to work as hard... yeah it'll rev up quicker, but that really will not hurt the engine.

There is a simple reason why cop cars and taxi's didn't have Olds 307.... none of the cars they used came with them lol.... thats like saying the 500 is weak, or the 4.9 is no good... just because they were not used for cop cars or taxi's dosn't mean it wasn't good.... think about it, when was the last time you seen an Oldsmobile Delta 88 highway patrol car?

Now on the same note, these cars were used for livery services... limos... I have seen lots of stretched 80's Broughams... and they have the stock 307, they don't have a problem, obviously the limo is not made to accelerate quick, but for the aveage wedding or high school prom etc... I am pretty sure the 307 did exactly what it was made to do.... now where are those strech Caprices?.... certain cars for certain uses.

the 307 was an after thought of an engine... after the HT4100 diasater, they needed something to throw in the car to let it live for a few more years... compared to the HT4100, the 307 had MORE horse power MORE torque, BETTER fuel mileage and FAR, FAR better reliability... so it was a win, win, win, win situation, then in 1991 after the slight face lift, they gave it the 305/350 to give it some more power... so I would say for the era, the intended purpose, and the car/engine, it worked out exactly as they hoped.

now comparing an Impala SS to a 307 car... define driving harder? taking turns fast? stopping short? none of that effects the engine..... do you mean accelerating faster?.... in that case the SS would accelerate as fast as a 307 car with about 1/2 the throttle input, if that.

With a 307 Brougham, to merge into traffic you gotta floor it. To maintain speed up a hill you gotta floor it, any time you need to pass anyone you gotta floor it... basically anytime you do anything besides leisurely take off from a stop light, you are running the engine wide open.

Now weather the car is accelerating fast or not, the engine is still running wide open, producing all the power it can, thus working as hard as it can.... now tell me what other vehicle has to work that hard (being ran wide open as often) as that.... I'll tell you, it isn't a Caprice 9C1 cop car, it isn't a Jeep, Peterbuilt semi truck, Silverado, Accord etc...

So I would say the 307 is worked rather hard in its life to get such a heavy car moving around.

Don't sweat it. The guy just doesn't understand the physics and doesn't want to think he's wrong. :bigroll:

"nothing you or anyone says will tell me otherwise"

The answer is to look at cars who's engines were extremely reliable. What kind of gearing do those have? Don't forget the overdrive factor if there is one.
I'm going back to my little corner now.

Obviously we can't forget the fact the most reliable engines were the engines that were properly maintained, lubricated, tuned-up, and cared for.

Obviously we can't forget the fact the most reliable engines were the engines that were properly maintained, lubricated, tuned-up, and cared for.

Er uh yes I believe that it is given that we are allowing for proper care. Quite.

I'm not sure gearing makes that huge of a difference, the engine still has to do the same amount of work to get the car moving the same speed. There are plenty of HIGH mileage 307 limos and plenty of HIGH mileage LT1 9C1s...

I'm not sure gearing makes that huge of a difference, the engine still has to do the same amount of work to get the car moving the same speed. There are plenty of HIGH mileage 307 limos and plenty of HIGH mileage LT1 9C1s...
No it doesn't. An engine with lower gears DOES work harder. It does not take a physics expert to figure that one out. Well, hell if Katshot is right, the 5.14's are going in tomorrow. :cloud9:

It's really hard to lug an engine with an auto transmission unless it is in lockup. Most will dump the lockup with a certain amount of throttle or a low manifold vacuum. An engine sitting on a flat spot cranking along at 1250 RPM while the vehicle is going 60 MPH is not lugging. Most heavy cars that get good mileage exibit a flat spot feel while cruising at highway speed.

All things considered, my choices are:

Carb'd, Olds V8's, 1968-1985 (86 was a bad year for Olds, blocks came from Mexico). Olds V8's are awesome, tighter tolerance than most any in GM for bearings, rings and pistons.

EFI, LT1, L05/L03, 3800 Series I VIN "C" (although not good for a heavy Cad).

I don't have any experience in a Cad powered Cad in RWD (my mom had a HT4100 1985 FWB). Just FWD, the 4.9L, which proved to be a good engine for me and my parents when they had it.

Modern electronics has made the biggest improvements. Electronically control trans, proper timing, proper fuel mix, less excessively rich mixtures when cold washing the cyl walls, modern emissions control, better power, etc.