TH350 to 200-4r

[teamplex65]

So I have done alot of research on this topic and actually started it last night. We got the new tranny in and found that the crossmember need to be slid back almost 6.5" . Everywhere I have read always says 3.5". Now I need to get exhaust redone (something I could of ovoided at 3.5"). Am I missing something here? I do not want to buy the $200 crossmember bracket they make but it doesnt look like it moves the mounts back 6.5" either.

I have a 65 Pontiac Tempest and am pulling a TH350 from a 79 TA and installing a 200-4r from a buick wagon.

Any ideas as I am stumped since every article says 3.5"

[Steve Chryssos]

I'm not real savvy on 200's. Is it the same overall length as your TH350? It's supposed to be--far as I know.

[teamplex65]

Oh yes, same length no driveshaft changes needed. Its the mounting holes. The th350 holes are about 8" from the tail, and the 2004r is about 1". We are fixing the problem I just know I have read 3.5" was the difference many times and was curious if I was missing something.

Steve

[rocketrod]

Your not missing anything, as you stated the overalll trans length is the same, but the trans mount is about 6"-7" farther back due to the overdrive gear. With that said, some have had success using a TH400 crossmember. I tried using a TH400 member, but I it interfered with the deep trans pan so I ended up buying the BTO crossmember for my conversion.

[teamplex65]

I am planning on just moving the crossmember back and redrilling holes. Thanks for the help everyone.

[Skip Fix]

Another thing you could do as you can do with a TH350 to TH400 swap is cut the mounting tab off the crossmember and weld it on the other side. Just about 6".

[Pro-Tour Heavy Chevy]

On my 71 I went from a th-350 to a 200 and still used the same x-member. The 200 uses the th-400 mounting holes in the frame, as far as how many inches back, I'd have to look it up.

[teamplex65]

We ended up sliding it back 6", drilling holes and tightning it down. It worked great.

Because it is 6" rather than 3.5" I will need to get exhaust work done which is why I was asking if I was missing something.

So far it has been a very easy install.

[JMarsa]

Make sure you get the TV cable perfect otherwise the trans will not last.

--JMarsa

[teamplex65]

Ah yes, I have 2 pages of steps to ensure the transmission is operating correctly. I need to go get a pressure guage for testing as that seems to be an important step as well.