Cadillac Owners Forum banner

1 - 20 of 31 Posts

·
Registered
1986 Fleetwood Brougham
Joined
·
77 Posts
Discussion Starter #1
Well, the "restification" turned out well, car runs and drives and looks quite nice.



I did a variety of mechanical and cosmetic work over the past month, which was not a ton of stuff actually. Spoke well of the condition of the car when I got it. All I lack is to finish off the pinstriping onto the rear fender fillers.

At 177K miles the original 307 is getting a little weary and I was mulling over options for replacement. Yes, I could find an Olds 350 to rebuild and install, but I started thinking about the Ford 4.6/4R70W drivetrain combination as a what if ....

Before the flames begin, in this case, I am not concerned about Ford in GM, GM in Ford, etc etc as long as the installation is clean and functional. In this particular model, purity is not a virtue - the 307 was a good engine, but would not be missed.

Anyway, here's what I was thinking about (pros):
  • As a current owner of 2 Crown Vics I am very familiar with the 4.6/4R70W combination
  • This is a proven durable and dependable drivetrain
  • CV's are plentiful and a complete engine/tranny/ECM is readily available and inexpensive
  • These engines work fine in larger heavier cars
  • Having an updated fully computer controlled injected engine is an advantage IMO
  • Fabrication/modification of engine/tranny mounts and driveshaft is not a problem
I'm not sure at all yet about oil pan vs crossmember, engine width, etc. so it is idle thought at this time. I know that LT-1's have been installed, etc, but I wondered if anyone had thought about the 4.6 installation. The 4.6 installation would include all peripherals, a/c compressor, exhaust, etc as well in order to use as complete a drivetrain package as possible.

There is still a benefit to using a 350/403 - obviously it's a bolt in and you use everything that's already there. So that is still certainly a consideration.

I'm more interested in technical info please, looking to avoid a branding war. At this point, the 307 is still ticking along, but it's never a bad idea to think about options before they are actually needed.

Your thoughts?
 

·
Auto Enthusiast
1992 Eldorado Touring
Joined
·
3,688 Posts
If you are going that far, you might as well go with a SBC 350. It will be far less work and will fit in your current engine bay.
 

·
Registered
1986 Fleetwood Brougham
Joined
·
77 Posts
Discussion Starter #4
When you say less work, can you please clarify? I'm assuming that I would just stay with the carb set-up that's on the car now? I have not checked to see if this engine will bolt up to the 200-4R that is in the car now. Incidentally, that tranny was a rebuilt unit installed last year, so it's fairly fresh, although other than a filter/fluid change and a look at the valve body, I cannot verify quality of the rebuild. It seems to work fine though.

Anyway, I do agree that there are a ton of 350's out there as well. If I went the 350 route then I would also go with a 700R4 as well unless the SBC is a bolt-up to the 200-4R. Advantage is about 60 cubic inches over the 4.6, but both drivetrain combos are readily available. The LS-1 would probably need something like a 4L80E behind it I suppose, I think that is a harder combination to find and higher cost when you find one in good shape.

Thanks for your input.
 

·
Auto Enthusiast
1992 Eldorado Touring
Joined
·
3,688 Posts
A SBC 350 will bolt up to your current 200r, but sadly that tranny would not last that long.

You can find a used 350 with 700R4 for under $700 dollars.

You can even do a TBI motor if you get the PCM as well.
 

·
Registered
94 Fleetwood Brougham
Joined
·
7,534 Posts
Honestly the Ford drivetrain would be more of a headache to do, and you would lose much of the electronics too. It is just a pain to do a nonstandard engine/trans. And that 4.6L is a tall sucker, might be a real problem.

A LS1 is sweet, especially a 6L LQ4. Toss in a 4L65E and have a killer combo with better mpg than the 307. 4L80E is hardly needed for it, 4L60E/4L65E is more than enough.

A SBC is also another great choice, bolts in, all parts are available for it in that chassis. The THM200 4R can easily be made to handle loads of power. Heck if you are going to SBC, a 700 R4/4L60 bolts in too with a shorter first gear. Out of the box the 4L60 will take a tad more power than the 200 4R, but not much, and reliability is just as marginal when run hard, on a stock trans, built, have a blast beating it....

The Olds 350/403 is a direct 100% legal bolt in. Legal in all 50 states. Even a Olds 400/400/425/455 if you can convince the inspector, even in California, it is still technically the engine family as the SB Olds, but just a tad wider....

Even a L29 454 would be a killer combo. You'll need a 4L80E for that one....

You can LS1's cheap on car-part.com. A 4.8L or 5.3L is a great all around engine. Toss in some 3.42 gears and you have a wonderful combo. Make sure you have a 8.5" axle. That is my recommendation. Might be a touch expensive initially, but if you are gonna keep it, the long term gains will be very very worth it.
 

·
Registered
1986 Fleetwood Brougham
Joined
·
77 Posts
Discussion Starter #7
Excellent info - thanks:thumbsup:

I did some measuring and the 4.6 would be fairly involved to install, plus it looked like the oil pan was going to be an issue. For a driver, I'm looking for a more straightforward approach and based on the info, it does not look like the 4.6 is really feasible. Yes, anything is do-able, but I don't need another project car.

All this leads me back to the 350 SBC. It can bolt to the existing 200-4R so intially I can just do the engine. I've rebuilt enough trannies that a failure does not really concern me that much, but if it cratered, I would go with a 700R4 at that time. Or I could just rebuild the 200-4R if needed, either way. If I remember right from just changing out the rear end fluid, the car has the smaller 7.5 or 7.6 rear gear. I would leave that alone simply to avoid more work. It should hold up to a stock SBC.

Now, for the SBC, are you suggesting to stick with or to do away with the electronic controls that are on the car now?

Sorry for all the questions, but thus has been a great help. Thank you.
 

·
Registered
94 Fleetwood Brougham
Joined
·
7,534 Posts
If it was me? I would look for a LT1, get the entire wiring harnesses, get a 4L60E and drop the whole kit and caboodle in. Parts cars are fairly easy to find for $500ish with all you need. Makes for a great combo, that will fit in that car nicely. You get 260+ hp, 335+ lb/ft torque. Mods are out there to make much much more if you feel the need. Reliability is phenomenal, rivaling most anything ever put on the non commercial sales market that hit the highways of the world. The SBC is the worlds cheapest engine to rebuild and maintain. So you can leverage that to keep your own costs down. L98 Z28/Vette/TA engine are also good choices, especially keeping the TPI intake, they make great low end torque, even better than the LT1 at low rpms where this car spends a lot of time.

I was going to mention the 500 Cad too, which includes the 472, 368 and 425 as a drop in. Just need a THM400 to handle it, any OD will be short lived on the 7.7L and 8.2L. The 6L and 7L would last a bit longer, depending on how well driven.
 

·
Registered
1986 Fleetwood Brougham
Joined
·
77 Posts
Discussion Starter #9
Aside from Camaros, T/A's, and Caprice, are there any other source cars for the LT-1's? I think that's the best bet, as you mentioned, get the car and get everything that's needed at the same time.

I would probably not go the big cad engine route due to greater availability and lower cost for the LT-1 and also I do not want the 3 speed tranny, for a driver I would prefer the 4 speed.

Many thanks for helping to clarify the choices down, greatly appreciate it.

PS - just a note on the electronic carb on my 86. I would recomment anyone to re-read the comments that N0DIH has posted in the 5.0 and 5.7 forum on rebuilding and adjustments/tweaks. I've worked on q-jets before and the info posted is great to help set the carb correctly and to be able to tweak it slightly as well. I had not worked on the electronic version though, but with the info posted and the info in the service manual it is running spot-on after the rebuild.
 

·
Registered
94 Fleetwood Brougham
Joined
·
7,534 Posts
Yup, all LT1's were regular gas engines... Looking at the Corvette timing tables, makes me think it was intended to be a premium fuel engine....

94 Fleetwood also is regular gasser...
 

·
Registered
94 Fleetwood Brougham
Joined
·
7,534 Posts
If you are shooting for 1 mpg better city/highway, the L99 might be a good choice. But often the L99's are frowned on, and there weren't as many made as the LT1. But any parts that work on a LT1 save pistons, rods and cranks, work on the L99 (265 CID, aka, 4.3L).

But the L99 isn't a bad engine either. The nice thing is too, the crank and rods from a L99 can be put in an LT1 and make an LT1 a 4.9L 302.

So the LT1/L99 can be made to work and work well. And have even some cool non stock applications.
 

·
Registered
None yet.
Joined
·
26 Posts
So are you saying a 94 FW runs on premium?? I am just going off of other cars (caprice,Impala) but the 94's also run on regular? :confused:
 

·
Registered
1996 Fleetwood
Joined
·
2,536 Posts
*whistle* I happen to have a Caprice serving as a parts car right now. I'd be willing to discuss a engine and tranny sale. The engine will start and if you toss coolant and a water pump on it, it's a solid motor. The differential is probably of no value though, since the accident involved the back wheels. Other things currently stripped off the motor involve plug wires, some hoses, and.... the ignition coil I think. The motor has about 130-150k on it, I can't recall. No fluid leaks or anything though. (I've been picking some parts off the car for a bit.) Oh, I'd prefer not to give up all the ac parts for it, since I'm currently having AC problems on my 96 Fleetwood. But, we could talk more if you want.
 

·
Registered
1993 Fleetwood Brougham (Sold)
Joined
·
48 Posts
I put a LS1 into my old Trans Am, dead solid performer and such a sweet smooth and reliable ride on the interstate (I've gotten over 30mpg in my severely lightened Trans Am - even if it was only once, on a cool day, on a flat road, and a four hour drive).

The small details in the PCM of the newer engines really make it a superior choice to the LT1 - the largest difference lies in the computer controls despite all of the nice materials and manufacturing upgrades to the LSx and LQx. Although I'd rather use an iron block LQx than any of the LSx engines for something that will see as much regular load as a ~4500lb D-body. LQ9 comes to mind :)

I just put a 383TBI into my '93. If I do this much work again I'd settle for nothing less than the new drivetrain systems. The modern engines are cheap for what they are and it's really not that big a deal to add it into something that was available with a Gen I SBC.

If you do install a LSx/LQx engine avoid the aftermarket wiring harnesses. I used a Street and Performance harness, (before the cheaper Painless harness was available) and these days I'd just use a straight up B/D-body LT1 harness and do the whole deal for slightly more effort.

However - the LT1 is the right solution for an excellent engine with the least headaches in a D-body.
__________________
1981 Pontiac Firebird Trans Am Turbo - LS1/T56
1993 Cadillac Fleetwood Brougham - 383 Vortec/4L60
1993 Mazda Protege LX - BP-ZE/G25M-R
1994 Mazda Protege DX - B8-ME/F25M-R
 

·
Registered
'93 Fleetwood Brougham...Dad's
Joined
·
4,382 Posts
So are you saying a 94 FW runs on premium?? I am just going off of other cars (caprice,Impala) but the 94's also run on regular? :confused:
NO. We clearly ruled that out, despite some misinformed posts:thumbsup:

It did in the Vette, but was tuned (among other small changes) to run on regular in these cars. Of course, you can also still do custom tuning and such to bump up certain parameters and make a B/D-body LT1 require Premium...but that's a whole other aftermarket thing;)
 

·
Registered
94 Fleetwood Brougham
Joined
·
7,534 Posts
If you have seen the timing maps (I have) in the LT1 Vette, yup, it is a premie.... With the larger cam and aluminum heads, the timing is very different than the B/D LT1....

All others are 87 octane.....
 

·
Registered
'93 Fleetwood Brougham...Dad's
Joined
·
4,382 Posts
I put a LS1 into my old Trans Am, dead solid performer and such a sweet smooth and reliable ride on the interstate (I've gotten over 30mpg in my severely lightened Trans Am - even if it was only once, on a cool day, on a flat road, and a four hour drive).

The small details in the PCM of the newer engines really make it a superior choice to the LT1 - the largest difference lies in the computer controls despite all of the nice materials and manufacturing upgrades to the LSx and LQx. Although I'd rather use an iron block LQx than any of the LSx engines for something that will see as much regular load as a ~4500lb D-body. LQ9 comes to mind :)

I just put a 383TBI into my '93. If I do this much work again I'd settle for nothing less than the new drivetrain systems. The modern engines are cheap for what they are and it's really not that big a deal to add it into something that was available with a Gen I SBC.

If you do install a LSx/LQx engine avoid the aftermarket wiring harnesses. I used a Street and Performance harness, (before the cheaper Painless harness was available) and these days I'd just use a straight up B/D-body LT1 harness and do the whole deal for slightly more effort.

However - the LT1 is the right solution for an excellent engine with the least headaches in a D-body.
GREAT post. As N0DIH has mentioned many times, the LS-based truck engines (5.3L/6.0L) seem like they could be a great match for one of these cars, and cheaper to get, as long as you can sort out all the wiring and computer needs.
 

·
Registered
94 Fleetwood Brougham
Joined
·
7,534 Posts
My personal opinion is 5.3L DOD engine is best, but no less than 3.42 gears, due to the higher rpm torque peak of the engine. Keep the truck intake is probably best for the heavy cars. 3.08's would be bare minimum in my book.
 
1 - 20 of 31 Posts
Top