500-200-4r, HELP!!!

[greencadillacmatt]

Hi Everybody!
This is my first post on here, and I need some help. First off, let me apologize if this has been asked before, but I am new to the world of engine swaps (havn't started the swap yet.) I have a 1984 Cadillac Coupe Deville, and want to replace the "wonderful" HT4100 with a 500. I can't find any info on how to bolt the 500 to the 200-4r. I have heard that there are flexplates out there to do this, but after 3 days of searching I can't find anything. Do I even need a flexplate to do this, or will the trans just bolt to the motor? IF THERE IS A FLEXPLATE TO DO THIS PLEASE TELL ME! I'm a college kid and don't have much money, so I want to keep the trans in there as long as possible. (Don't have the money to redo a TH400.) Hence my problem. Sorry for the long-winded post, but that is all I need to know for now. Thank-You for any and all information, it is greatly appreciated.

[urbanski]

howdy and thanks for joining! some smart folks will be by shortly to answer and good luck

[hardley-etc]

what year is the 500 from
torque produced from the 500 might twist the frame and damage the tranny
does not seem to be a good idea without additional preperations

[elk9300`]

http://cgi.ebay.com/ebaymotors/SFI-F...mZ110286861708

[cadillac_al]

The 200r4 should bolt to the 500 without much problem. I wouldn't be surprised if the 500 flex plate has both bolt patterns on it. If not then the 200r4 converter probably has the same bolt pattern as the th400 that was on the 500. I think you're bigger problem will be the frame mounts. Check out csbuckins engine swap thread for insight on that dilemma. I think a 305/350 Chevy engine would be the easier swap. You might have to look for 1980 368 frame mounts to use the 500.

http://www.cadillacforums.com/forums...gine-swap.html (My first engine swap)

[elk9300`]

There are 2 bolt patterns. A wider one and a smaller diameter one.
If you go to my previous post, click on the link and look at the pic, you will see that there are two sets of holes. Been there and this solves the problem.
If you use the original flywheel from the 500 ci/TH 400 these holes would have to be drilled out along the stress ridge.

[greencadillacmatt]

I think that if I use the 368 motor mounts I should be fine in the frame mount problem. The motor is a '76 out of an Eldorado (Non-Fuel Injection). It needs a carb and pistons. (I don't have it yet, but am waiting the guy to get back to me about it.) He bored it .040 over, align-honed the block, and installed new cam bearings. It is all taken apart, but complete. He also has the origional 500 motor mounts out of a deville, along with deville headers. So I don't have to worry about that. I'm not going to do much to it in the performance department now, (college budget) but I am going to put in the bigger pistons. Will the 500 motor mounts work in the car since it is the same block as the 368? Thank-you for all your help, everybody. I will try and post some pictures of my car soon.

[cadillac_al]

It sounds like you have the frame mounts covered with the 368 mounts. I'm not sure if Eldorado motor mounts are the same as Deville mounts; somebody here will know. The 500 was bored .040 without pistons? I'm worried about that. I would much rather buy a running 500 that I could hear run. Good luck.

[greencadillacmatt]

The enginge is 99% complete, it just needs the bigger pistons since it was bored .040 over. That shouldn't be too much of a gamble, right?
Also, I know that you have to "clearance" some of the bolts on the A-arms on the deville if you use the 500 headers, but I have heard that you can use 425 headers and you don't have to even mess with the bolts. Is this true, and if it is, would it constrict the exhaust badly from the motor? Thanks in advance. -Matt

[elk9300`]

I think the Eldo mounts may be different. In looking at the block where the mounts go, they usually cast two different sets of holes for RWD and the FWD since the engine is a little bit more to the front of the car (at least I know this is the case for the engines including the 368 used on the 79 and later Eldos)

[zonie77]

Do some reading on 2004r's.

I've seen a change to a 700r4 filter and a deep pan as important to long life. In perf applications the filter can get uncovered during hard launches and the trans run dry under full load. You may not notice it but it burns the trans up quickly.

[greencadillacmatt]

Thanks for all the great info, guys. How hard would it be to put a TH-400 trans in this car? I know that you can get a crossmember for it from CadCo. Is this all that you need, or is there other stuff? Kind of scratching my head as to whether I should put a TH-400 in it, or just keep the 200-4r in it for now and see what happens. So all info helps. Thanks again.

[elk9300`]

Th 400 shouldn't be a problem. You will need the kickdown switch. But it has the flywheel, and there are plenty with the BOP bolt pattern.

I kept the 200-4R in because I wanted the overdrive and to try to keep it stock. The 200-4R will not grenade unless you beat the snot out of it without some internal beefing up.


I know that there are places that build them for GNs and in the previous post, cooling and filters are key. I do have a deep pan for mine and an external cooler. I will also be running an auxilliary filter for the tranny and the coolant. These will be hidden, but will allow good maintenance.

[greencadillacmatt]

Well, the 500 deal with the guy on e-bay fell through. I'll find another one, just a matter of time. As of which, does anybody have a 500 motor (preferably a rwd model, but I don't care if it isn't) anywhere near the michigan area? Thanks in advance.