: Had to ask about a engine swap



Big_Blue
02-21-05, 09:44 PM
I have a 1986 fleetwood brougham(Rwd) with the nightmare 4100 motor. I have obtained a 1979 Devile Coupe(Rwd) with a 7.0 engine. The Coupe has the worst case of rust I have seen, I mean I can prolly punch a hole in the trunk with my hand. The Former owner had the car sitting next to the garage with constant slow drip of water on it. It has 60k orig miles on it. The motor looks great and runs like a charm with very small rust and with old belts . I was curious to know if I can swap the motor into my current love mobile and what it would consist of in the process. I have read other post of members doing swaps but not clear on my year.

What I want to know is it a direct bolt in of motor and tranny and what would it take to get it in.

I would do a rebuild to be sure along with tranny work

davesdeville
02-21-05, 10:56 PM
Should be quite easy as far as engine swaps go. Might want to swap the rear diff before you break whatever weak one they stuck behind the puny 4100.

Big_Blue
02-22-05, 12:53 AM
Do I use the existing mounts from fleetwood or the deville mounts? Do you know any thing special I am going to need to do? I mean I never did a swap before but I really dont want to pass this up. The deville motor still has the factory blue on it from the dealer I guess it came from .

N0DIH
02-22-05, 02:13 AM
Should be quite easy as far as engine swaps go. Might want to swap the rear diff before you break whatever weak one they stuck behind the puny 4100.

Granted those rear ends are only 7.5/7.625", they hold up for Monte Carslo SS power. And most 82 up Camaro/Firebird have 7.5/7.625's also (unless you got stuck with the goofy 9 bolt Aussie rear). Just don't put slicks on and you are fine. Don't recommend beating it either... But it will survive average driving. The Cutlass's all had em in the 80's, and with 2.56's were rated to tow 4000#. Not too bad if you ask me. A friend of mine beat his 2.29 7.5" rear to the tune of 14.5@106 mph for weeks on end before it came out. (78 GP, 400 CID Pontiac, killer Lunati cam) Such soft metal the teeth were all curved, but not a one broken. All LS1 powered T/A's and Z28's have the "wimpy" 7.5/7.625" rear end. They survive.

And the 4100 cars all have 3.42's unless you have a high alt car, then you get 3.73's.

With those gears it should be a great driver, but sucks on gas, unless you get an OD back in it. The 7.0L should mount to any THM200 4R with no issues, just need to beef it up seriously. And they have the better 2.74:1 First gear and .67 OD ratio.

Tom

davesdeville
02-22-05, 02:35 AM
I think the mounts for the deville will fit the fleetwood frame. You should be able to take some measurements and see.

A TH200 with 7 liters of engine is just a bad plan.

90Brougham350
02-22-05, 10:43 AM
If you're willing to spend just a little extra, I would try and find a 700-R4 from an old Caprice or Parisienne or just take the tranny along with the engine.

Brian

N0DIH
02-22-05, 02:11 PM
Given a choice, I would trust a built up THM200 4R over a 700 R4 any day. The first gear ratio is lousy for torque motors like the Cad 425. And if you can break a THM200 4R, you can break a THM700 R4.

They both need to be built, the 200 4R's come with BOP and Chevy pattern, 700's are Chevy only. So you need an adapter plate.

Look around the net for Yank's 4L70 trans, it was featured in a High Tech Performance mag or a Chevy Craft Mag, maybe even Pop Chevy Craft, it is what he dubbed his beefed THM200 4R for a Z28. Level 10 and Art Carr (not the Art Carr transmissions shop, Art himself, he sold his name on the business) have great stuff and lots GOOD to say on the THM200 4R over the 4L60/700-R4.

You will have rebuild it anyway. If you run 3.42's and a THM350 or THM400 it will just suck gas badly. But won't need a rebuild just to live.

I have read the THM200 4R's are stone stock designed for 275 lb ft torque, and the 700's are 325. But the gearset in a 200 4R will survive much more power than a 700's. The main thing is clutch surface area and accumulator capacity. Most hard parts survive a lot of power.

Remember, the older V4P packages had THM200 4R's too. Not sure which code trans it was, but they were designed to take some punishment too. As for how long they would live.... Anyone's guess....

Question, did the Caprice/Parisienne ever get the 700 R4? I didn't think so, only the 9C1 cars AFAIK. I'll do some digging in the parts books.

Tom

davesdeville
02-22-05, 07:38 PM
I wouldn't have anything short of a TH400 or 4L80-E behind my big block Caddy.

Big_Blue
02-22-05, 09:24 PM
I appreciate all of you guys input but in response to 90brougham350. The 79 Deville final destination is a junkyard. I am trying to pick the motor out and whatever else that might be needed before more hands get in the cookie jar if you know what I mean. If I can get a free smooth running motor thats way way better then the 4100. I would be very happy :):):):):).

Also I am working with a small budget and getting the big hardware for free is a super plus.

luddyludwick
03-10-05, 02:30 AM
No, Caprices never had the 700R4, or at least not in the old body style (up to '90).

As for building a 200R4, I'd do that rather than the 700. It can be built by any transmission shop worth their keep; also, the 200R4 is designed to lose less power than the 700, so that should help.

If you have an 86, you do know it's a 307, right? If you have the 82-85, then it is an HT.

Also remember that cruise is through the computer on the HT; you'd lose it in the engine swap and need a vacuum one from the 7.0L...engine mounts are also going to be an issue...

90Brougham350
03-10-05, 01:51 PM
No, Caprices never had the 700R4, or at least not in the old body style (up to '90).

http://www.autopartsfair.com/chevy-transmissions/caprice-catalog.html

Yes, Caprices and Parisiennes came with 700R4s. Of course they did. Go to any junkyard and climb under one. I'm not trying to argue, but a stock 700 R4 can take more abuse than a 200 4R. There's a reason they put 700s instead of 200 into trucks. Plus, if it's going behind a 7 liter, the deeper first gear of the 700 will really launch, while the torque of the 425 will take care of the 1/2 shift and so on. Now, I know you're all going to disagree with me, but as a matter of personal preference, I'd much rather take a 700 any day. I keep reading how a 200 can be built to take so much. Well, a stock 700 takes more than a stock 200, and a built 700 takes more than a 200. But since this project is on a budget, the 200 will work fine.

Brian

davesdeville
03-10-05, 06:05 PM
I'd just take the engine, tranny, and rear from the 79. It's the same frame so it should all work just fine. A TH400 is the best choice IMO, no need to build it to be strong, plus its gearing should work well with the rear from the 79.

luddyludwick
03-11-05, 01:46 AM
My bad about the 700...I forgot that the SBC 350 was offered as an option. I always have a block in my head that tells me the 80's caprice only came with the 305

evilrussian
03-11-05, 05:12 PM
You can go with 200-4R, I have it behind a chevy 350 and after 5 years (I just dropped the pan to do some work) it looks pretty good, no excess metal in the pan. I know that 425 is a whole different animal but 200's can do well if you beef them up a little ( I've had a shift kit and just installed a billet servo last weekend, yet to test it)