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Discussion Starter #1
so I got to thinking how much the BB Cad's like to tug...

and I was wondering, lets say a 500 was built up with hig torque/low RPM in mind (then again, what BB Cad isn't?) but to work with the 2.28 gears, I mean alot of power avalible right at 1,000RPM, and a redline somewhere around 4,500RPM or so....

it would be almost like building a towing/RV motor, but with a bit more top end and rev happy....

I just think it would be cool to maybe stick with the 2.28's (add a Posi) because its soo cool to stay in 1 gear for ever watching the revs slowly climb, while the guy next to you is banging gears like no tomorrow.

Plus, the stock 425 pushed the 2.28 farily well, it now has the modified 472 intake manifold and rebuilt carburator, which my father said made a nice difference (I havn't drove it yet).... and a mild build on a 500 will easily double the HP of the 425 and nearly double the torque.... so it would be hard to imagine an engine with twice the power/torque pushing the same car that is already fairly powerful as it is.

Also, the stock 425 spins the tires easy enough with 2.28 gears... throw a built 500 in there with 3.08's or even 2.78 (what I would want) and I think traction would become a huge problem on street tires (what it would have) so the 2.28 gears would help in that case as well.

Also, the 2.28 gears would be good for keeping it a driver, the revs would stay low when crusing on the highway etc....

Basically the idea would be to keep the power band and the properties of the engine to nearly what they are now, maybe raise the redline a tad... but make the thing a massive torque pig so that Honda boy next to you dosn't understand how a huge Caddy can accelerate from 0-60 in first gear and still pull on him....
 

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Discussion Starter #3
It would be for the 500.

I mean, if I can find a nice set 3.08 Posi from a similar year commercial chassis or factory towing package, that would be nice.... I thought they were 2.78, but I was corrected.

I dunno, I just wonder if there is hope for the 2.28 gears, and any any market Posi unit should fit, its a standard 8.5" 10-bolt GM... the gearing shoudln't matter.

It would definitly be good for 1/4 mile... only gotta shift once :)

Just seems to me like the stock 425 pushes the 2.28 gears farily well, a built 500 could do much better.

Most of all, the '79 stock, bogs from a stop, around 30mph once it is in the powerband it actually pulls better.

Plus how cool would it be to cruise at 70mph on the highway, downshift into 2nd and floor it, and pull like a freight train past 110mph.... in 2nd gear? :)

it would be the total oppsisite of new "tuner" cars that bang thru gears and the RPM goes up and down soo fast... this would be dragging the RPM out while the car accelerates fast.

I think a high torque/low-RPM setup would be over all better too... valve train would be easier to build up and stuff.
 

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2.28:1 Cadillac rear axles are 8-7/8". The guts are heavier than 8.5" axles.
You will take off much better with a 2.73 or 3.08 gear set. A 500 doesnt' have enough power in that chassis that you cannot get it to the ground with street tires, even with a medium stall convertor. If you modufy the engine for more hosspower then the touque curve will move upward. Now if you wanted to keep those gears for gas mileage the story changes.
 

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not meaning to highjack the thread, but...

Ape do you think that you could help me with choosing a torque converter?
 

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terrible one said:
not meaning to highjack the thread, but...

Ape do you think that you could help me with choosing a torque converter?
Not really. There are a lot of people who know more than myself on this subject. I'll tell you all I know in 7 sentences. Once had a B&M TH400 converter in my '77 CDV. Cheapest convertor they sold. don't remember any specs. The car felt a lot faster with it. Stock converter was pretty tight for economy. Never got it to the track. Years later I swapped the same converter into my '82 Trans Am which had a 500 fitted while the 2004R was out and at the trans shop. The Car really flew but gas mileage was half that of the lockup overdrive trans. Not very scientific eh?
You need to know something from yesterday about Cadillacs, I'm there.
 

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Discussion Starter #7
I thought I remember reading in the manual it was 8.5".... but then again 8-7/8" sounds familer.

Thats pretty much what I figured, the 2.73 would be much better for me.... I was just hoping I may be able to get away without having to switch gears.... it isn't that its a big deal, but I can't find ANYTHING for this thing.
 

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You need a posi. That body style needs a posi even without any performance mods. My '80 CDV that the wife used to drive needed (and got) a posi.
I've only seen 1 2.28 posi in all my 25 years of looking. It was in a loaded '78 CDV. I still have it here and might put it back to work. It's been in 4 different cars over it's life! The thing could use a new set of gears but IIRC only up to 2.56 will work. I have all the part numbers for these years if you need anything looked up.
 

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I thought the old Pontiac sourced rear (2.73s IIRC) were the 8 7/8s. But I haven't tried to find out that info in years so hell if I know.
 

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davesdeville said:
I thought the old Pontiac sourced rear (2.73s IIRC) were the 8 7/8s. But I haven't tried to find out that info in years so hell if I know.
Were you swapping rear ends when you were 13?
 

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Discussion Starter #11
Something I thought that would be neat.... going in the total oppisit direction of high-power....

2.28 gears.

425

the cam from MTS for fuel economy (#3 IIRC?)

rig up the 368 cylinder deactivation features

*MAYBE* swap in a 700R4... though the OD may bring the RPM too low....

in the '77-'79 chassis

I am thinking *almost* 30mpg on the highway is possible.... MTS said somone got 22mpg in a '76 DeVille... 1,000lbs heavier, and with a 500.

smaller engine, smaller car, cylinder deactivation.... the thing would run the 1/4 mile in about 25 seconds... but damn, get up to crusing speed, cut it back to 4cylinders and get 30mpg in a '79 Caddy.... possible?

Not that I would do that... only way I would make the '79 a fuel econo car is if I had something cool to put a built 500 in..... like a '68 CDVC or a '72 Eldorado convertible :)
 

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'92 Eldorado convertible will fit a 500? Do you mean '72 Eldorado?
 

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Discussion Starter #13
I~LUV~Caddys8792 said:
'92 Eldorado convertible will fit a 500? Do you mean '72 Eldorado?
yeah... wow... '72..... changed it..... gosh these sleeping pills are doing a better job at mimicking the effects of being wasted, and not making me sleepy.... ahhh
 

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JTraik said:
Were you swapping rear ends when you were 13?
You and Ape man can piss off. I got the car when I was 15 and have been reading about it and its motor off and on (mostly on) since then.
 

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Looks like someone pushed a button eh? Junior high is over. You aren't going to get too far if you can't get along with other people. Actual automobile repair and restoration work can be therapeutic. It will go a long way building first hand knowledge. Much better than drooling over speed parts on the internet.
Sorry for the thread hijack.
 

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To gain in performance, you need to go up on the cam......when you go up on the cam, the power band moves up the rpm range......to get the most out of that power (as far as street driving goes), the gears have to go up (numerically) also. In order for everything to work correctly, everything has to work together. A cam designed for higher rpm isn't going to work well (on the street) with gears designed for low rpms.
 

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The Ape Man said:
Looks like someone pushed a button eh? Junior high is over. You aren't going to get too far if you can't get along with other people. Actual automobile repair and restoration work can be therapeutic. It will go a long way building first hand knowledge. Much better than drooling over speed parts on the internet.
Sorry for the thread hijack.
:want: :canttalk: :histeric: :duck: :D
 

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Hey dont pick on davesdeville, he just asked a simple question and got a sarcastic answer. What did he do wrong?
 

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Discussion Starter #19
lux hauler said:
To gain in performance, you need to go up on the cam......when you go up on the cam, the power band moves up the rpm range......to get the most out of that power (as far as street driving goes), the gears have to go up (numerically) also. In order for everything to work correctly, everything has to work together. A cam designed for higher rpm isn't going to work well (on the street) with gears designed for low rpms.
Thats pretty much what it comes down to... and in any of the BB Cad's, the cam is one of the limiting factors... so larger cam is needed, thus the gears are needed also.

I don't want anything shorter then a 3.08, so exactly what years and models come with the 2.73 or 3.08? These are both 8-7/8", right? Posi is optional on any of them, and there would be a tag on the cover? and how can I make certain of the gearing?

I am going to start hitting the junkyards here in FL and want to keep an eye out.
 

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AFIK the '77 + Cadillacs didn't come with any gears other than 2.28 or 2.41 up to 1981. Not to worry. Generous motors axles from other lines can be fitted. Limos might be another story but I've not seen them.
 
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