I am still debating on doing the engine swap into my 91RS especially since the 305 died. Do yall think it is possible, I am almost sure I will have to go with ported stock exhaust manifolds because of clearence issues. I shouldnt have any problems with the firewall because it has a front mounted distributer. What about engine mounts???

 

My uncle owns a shop that specializes in Caddilac Performance, you'll definatelly need new motor mounts. The big block mounts are in a completely diff spot than a small block chevy. You'll probably need new everything too. from radiator to a special mount that will allow you to bolt up your tranny if you plan to keep the 700r4. You might have to do some fabrication to the firewall and inner fender to fit the engine not to mention that it won't pass emisions in you have those out there. your probally looking at $6000 for a good strong motor and another $3000 in fabrication. Oh yeah and when parts brake they will be really expensive. Good luck, if you do it it'll be one of the best thirdgen's ever

 

I have a TH400 to back it up with and a BBChevy will fit with headers and still have about 1inch clearence so I dont think I'll have a problem with that. Do you know where to get a a conversion motor mount because I have heard they make them but I am not sure by whom. I am just going to put the engine in stock because it run real good as it sits and my budget is pretty tight because my IROC is my main priority. I will convert to a mechanical fan to help the cooling with a real low thermostat until I can afford a becool rad or something similar.

 

Well you can contact a shop out here in albuquerque NM, called Flash Automotive. They own a caddilac performance shop called cad-company. I believe that they make the mounts and all the parts neccesary to swap that motor in. I don't have the number right now, but I'll post it tommorrow. I was thinking about putting the 500cid caddy in my 86 trans am, but the engine alone was more than I paid for my car, so I went with the a 355 small block, much more affordable.

 

I have an 84 trans am and am in the process of putting in a 500 caddy. Ive got all the mounts done, and the manifolds needed a little grinding, but it is sitting in my car. Im taking it back out and sending the block to the machine shop. I had to make new mounts that stick forward a lot, and brace them on the frame sides, but other than that I had no problem. The oil pump was perfect, and I had to relocate the electric fan to the front of the radiator. The engine has 7 inch rods with forged olds 403 pistons. The heads are ported and I guestimate ill have around 10.2.1 compression. It should be pretty bad. Im getting a turbo 400 built with a 2000 stall, and im working on a ford 9 inch with 3. 25 gears. Im making a hood scoop for the intake clearance. I would say if you like to fabricate and spend a lot of time on a car then definately do it. If you dont, then i wouldnt recommend it. Once I get it running in about a month, i will post a message on the mts message board. Good luck

 

Your the guy I was talking to on 500cid.com.

 

Well, my names matt on the message board. i forgot to tell you that I had to custom make an oil pan, because of the exhaust. I used a 3/4 sump and cut the front off and extended the sides, so the exhaust could go behind it. Well if you have any questions e mail me.