jonstringer

I have a 1972 Olds Cutlass S w/ a 455 ci, TH350 transmission, and a 2.73 open rear. I want to convert it to a 2004r OD transmission with a 3.73 posi. I'm sure quite a few of you have done this conversion, so I go to you for advice.

1. From tranny core purchase, to HD rebuild, what am I looking to spend?
2. What fabrications will need to happen to retrofit this transmission in the th350s place. I have heard that they are the exact same size, and that no mods are necessary for this swap.
3. Will the console shifting linkage work properly with the 2004r?

I am all ears. I can learn from your success and failure in converting your car. Thank you for any advice you may have.

jon

68conv455

I'm still in process with the swap. But I can tell you some things.
1. For a core, general concensus is the 86 or 87 buick GN trans with the BRF valve body. At the end of the GN run, most of the bugs were worked out making these the best of the stock tranny's. Because of their popularity, cores will cost you. I've seen cores for 200 and running transmissions for 500. I've got a so called good running 1985 GN transmission for starters. I plan on debugging the car with the stock transmission before investing in one built to withstand abuse. I'm leaning toward CK performance for my built unit. Just the trans will cost close to $2K.
2. The trans is the same length as your TH350 and the Yolk is also the same. You will need to move the cross member toward the rear of the car. My 68 cutlass already had factory holes in the frame for this. You will need to get a TV cable and appropriate mounting bracketry/plate for your carb. You will also need to incorporate a convertor lock-up switch. I've heard some people say the TC bolts don't fit through the 455 flexplate. Mine fit fine.
3. I've seen shift detent plates made for stock style floor shifters. The kits come with new D N R etc strip also. I'm not sure where but if you look around I'm sure you'll find one. I've deleted my column shift due to headers and am going with a B&M Megashifter.

On a side note, a 3.73 may be scary on the street with the 2004r. First gear is lower than your TH350 so the 3.73 will actually feel higher when you combine the two. I've planned a 3.55 rear for mine.

Good luck.

olds455

Ive just got my 200 4r installed behind my 455. My core came from a 89 caprice. I built it to handle 800ft lbs so I got alot into it. About $2500! Just like 68conv455 says it bolts right in. I also had a th350 and just moved the cross member back. the drive shaft went right in. Im keeping the column shift in my car but check out a place called shiftworks. They have detent plates and other goodies. If bought from them before. .

Im having a issue with the torque converter and flexplate.

Shizzy

im also in the middle of it.

you are going to need metric bolts for the converter.

Motormite/Dorman P/N 14040
Type: Torque Converter Bolts
Description: M10-1.50 x 15mm Class 9.8
OE#:

Also, if you currently have a TH350 you parking brake cables are going to either need to be replaced with the TH400 set or you will need to rig up a way to get them hung correctly under the car.

I used the Painless wiring converter lock up deal and it was simple as pie to install.

If you are still running a Quadrajet, you may run in to issues of where on the linkage to hook up the TV cable.

I picked up a Monte SS tranny. from what I hear the GN and Monte trannys are the ones to get. However, if you are going to have the tranny gone through and beefed up I dont think it will matter what it came out of.

turnpike_cruiser

That would be http://www.shiftworks.com/kits.htm

I used their kit #SC2312 when I installed my 700R last year. Here are a few photos of the installations.

442much

I've got the original TH400 in mine (with the 455) and a dual gate...so I guess my choice would be to choose between the transmission or shifter. On the other hand, the tranny is guaranteed for life so I suppose there's my choice.