Just wondering if and what it would take to make this work?....I was just thinking about getting a 500cid crate engine, some aftermarket supplies off MTS, and a powerglide tranny to drop into either my 71 coupe or 77 coupe. Most likely the 71....Opinions?

If ya wanna go fast then stick with the '77. You might look into using the turbo 400 instead of a powerglide.

The thing is, is that I just rebuilt the 425 to the '77. And the '77 actually weighs more than the '71 one I have. Weird huh? So a crate engine with the stock TH400 and something like a 750-800 cfm edelbrock or demon carb along with a comp cam would be pretty good? One more question...could I throw on some 472 heads (possibly shaved) onto the crate engine?

There's no difference between 472 and 500 heads.....a 1970 500 out of an Eldorado will have the same heads as a 1970 472 out of a Deville. Small chamber heads (used from 1968-1973) were basically all the same as were the large chamber heads (used from 1974-1976) whether they came from a 500 or 472.

How the HELL does a 77 outweigh a 71? Anyway you don't want a 2 speed with a heavy car like these. The TH400 is the best if you don't want to drop at least a grand on a 4L80E which is the TH400's overdrive-including cousin.

We've been over the carb issue a LOT and while those with aftermarket carbs usually don't have a problem with them, the majority of us believe a Quadrajet is indeed the best thing short of MPFI for performance and fuel economy until you get into the really high HP range.

If you're getting a crate engine from MTS, why not just have MTS shave the heads and put in one of their cams if that's what you want?

Oh...I completely forgot that MTS has crate engines. Great idea. I've always had good luck with edelbrock and was just thinking about getting a carb from them, or try a demon. How much do rebuilt Qjets run? Thanks.

oh, and the 77 weighs in at 5700 lbs, and the 71 is at around 5200 lbs. i couldn't believe it either...

oh, and the 77 weighs in at 5700 lbs, and the 71 is at around 5200 lbs. i couldn't believe it either...

You must be looking at GVWR not curb weight. The '77 CDV is right around 4000 Lbs.

Oh...I completely forgot that MTS has crate engines. Great idea. I've always had good luck with edelbrock and was just thinking about getting a carb from them, or try a demon. How much do rebuilt Qjets run? Thanks.

Well finding a running core doing the work yourself is obviously gonna be cheaper than having MTS do it. Starting with a non-running core engine will probably still be cheaper. CadCo also will ship you a turnkey engine so make sure to check with them also. A rebuilt QJet (or a rebuild on a QJet for that matter) is around $200 and up I believe. Maybe cheaper if you can find a local carb shop to do it.

I talked to MTS and their blocks run $150 and all it includes is main caps. But, he said that they are getting ready to make new rods and pistons for the 472/500. He didn't get into full detail but he said something along the lines of putting the 500 rods and pistons into the 472. I didn't get the guys name that was telling me all of this, but I did get that the 472 would be a little quicker on the street than the 500. But, the downside is that he estimated it would run $1,200-$1,300. Hopefully I can have this done in the next year. One more question...since the the '71 is over 25 yrs, I could probably have a true dual exhaust without any problems from a shop, right? And not worry about an H-pipe if I got the headers for it?

You must be looking at GVWR not curb weight. The '77 CDV is right around 4000 Lbs.

Can't be GVWR on the '71 at least. My '70 SDV weighs in at 5520# scale weight with two people, spare tire, and a full tank.
Don't believe the shipping weight that some sites have, they claim my '70 should be nearly 1000# lighter. LOL :helpless:

Alright. I've decided to rebuild a complete engine instead of getting a crate. I figured I could start with a core and then I would know exactly what is going into it. Just a couple quick questions...And I'm trying to make this the biggest, baddest engine I can.

If I get the 472, can I throw the 500 pistons, rings, etc... into it? (Considering what I was told, it would make it a little quicker) And, what would be the most I could bore it out. I know I could go to .060 over, but I was thinking more along .040. What do you think about the forged domed pistons?

B&M sells a racing version of the TH400. Is it worth it? And should I get their Holeshot 3000 torque converter with it along with their flexplate?

Anyone had any luck with the aluminum heads from MTS? I'd imagine so...

What is the website for that Cadco?? I can't find it...That's it for now. I'm sure there will be more soon.

Alright. I've decided to rebuild a complete engine instead of getting a crate. I figured I could start with a core and then I would know exactly what is going into it. Just a couple quick questions...And I'm trying to make this the biggest, baddest engine I can.

If I get the 472, can I throw the 500 pistons, rings, etc... into it? (Considering what I was told, it would make it a little quicker) And, what would be the most I could bore it out. I know I could go to .060 over, but I was thinking more along .040. What do you think about the forged domed pistons?
You can make a 472 a 500 but you will need a 500 crank and pistons. Putting 500 pistons in a 472 won't make it quicker. What MTS was probably saying is that because of it's shorter stroke, a 472 will rev quicker and could possibly be a little quicker in a lighter car. Personally, I doubt you'll really notice it much.
.040 overbore is great if that's what you want and what the engine needs. Most of the time these Caddy engines need very little to clean the cylinder walls.
Forged pistons are good if you plan to run any power adders (nitrous, blower, turbo). If it's just going to be a mild street engine, forged slugs may be overkill.

B&M sells a racing version of the TH400. Is it worth it? And should I get their Holeshot 3000 torque converter with it along with their flexplate?
As far as I know, B&M's trannys are decent units but a reputable, local tranny shop should be able to hook you up with a good TH-400 for about the same money.....maybe less.
The converter depends on your set-up. Once you're sure what cam you're going to use and what gear you're going to run, you can get ahold of a 'verter manufacturer and they'll be able to tell you what you need.
You need a Caddy flexplate and I don't think B&M sells them.

Anyone had any luck with the aluminum heads from MTS? I'd imagine so...

What is the website for that Cadco?? I can't find it...That's it for now. I'm sure there will be more soon.
The Bulldog heads are decent from what I've heard. I'm not sure if anyone has any though.
Do a google search for "Cad Company" or "Flashcraft". Some of the other companys are Torque Inc. and Potter Automotive. Check out the page that davesdeville has set up (I think you can find it in his profile). It has most (if not all) of the big block Cadillac vendors listed.
Good Luck.

Cad Company's site is http://www.cad500parts.com

My site that lists every parts vendor for 500s is http://www.500caddy.us - then click vendors on the left side navigation bar.

The Bulldog heads have had some serious problems, but perhaps they've sorted it out by now - check with the vendors...

What kind of problems are we talking about with the heads? I'd hate to put 5k+ into this engine and have it blowing up under the hood? If that's the case, I'll save that 3k and get a 500 with the cast iron 76cc heads. And like I've said...I want this to be a balls to the wall motor. I'm not sure I want to race it yet, whenever it gets done, but I just want that option open...just incase. I just want the meanest motor that I can make without having to weld or cut pieces to make them fit. I would just want things that all go together very smoothly.

Then talk to the vendors... some of the heads were just poor castings I believe. I don't know if they even are making more of them currently... Just check with the vendors. I haven't looked into them that much since I can't afford them.