Looked into getting the Trans-Go kit for pump and valve body, new converter, lost the old one, and a kit for the lock up so it locks in 4th, generic kit on eBay for around $50 I think it was, new lock-up solenoid and some other items, then since the TH400 is from a Centurion in there, need a longer driveshaft, of which I am hoping there is still one in my garage from a cutty, so having the shaft and trany, out of pocket costs for upgrade would be just over $300 with fluid. Not too bad I think..
But the 200-4R would be great addition if beefed up a little, or if you can find those 3 letter coded tranies that were built better, this caddy had 80k on her, trans been on the shelf in garage nearly 20 years now, rolling dice not going through her all the way, but work has been slow, might wait until it picks up and do it right, but if I do have to pull it, at least not a FWD...
does anyone have info about what modification they made for the gear selector?
Thanks Jim, very informative. Thanks for the part numbers. Will be very useful.I did this to a '68 Skylark about 2 years ago. Pretty straight forward. Overall the Turbine 300 (Buick Power Glide) and the 2004R are the same length. So the drive shaft length doesn't change. The transmission tail shaft mount pad on 2004R and the THM400 are the same distance aft of the engine. So in my case, since my Skylark 350 had a Turbine 300, I had to move the transmission cross member rearward to the THM400 position. The holes were already there in the frame since THM400's came behind big blocks in GM A-Body cars. The shift linkage and the speedo hooked right up. There is plenty of shift lever travel but the indicator is a little bit off for gears below drive. I had to make transmission cooler lines since I couldn't find any stock lines that would match up. You will need a TV cable and a stud on your carburetor throttle plate linkage to hook it to as well as a bracket to secure the carburetor end of the cable sheath. I run an 840 Q-Jet that came with the stud and got the bracket from Summit Racing. The TV cable came from PATC-Performance Automotive. If you decide to run a lock-up converter, and I would, you will need to modify the transmission valve body controls with a kit from TCI. The part number is TCI 376600. You will also have to add a 4 terminal brake light switch. One set of terminals is normally closed for the brake lights and the other is normally open for the torque converter clutch. When you hit the brakes the switch goes to the open position and drops out the converter clutch. Painless Performance part number 80176. In the TCI kit you also get a vacuum switch that won't let the converter lock-up unless the manifold vacuum is high. The TCI kit also limits converter lock-up to 4th gear. Be aware, the 2004R is a close ratio overdrive transmission. 1st gear is is not real deep like a 700R4, so deeper rear gears are necessary. I used 3.43:1's but probably should have gone deeper like 3.64's or 3.73's. At .75 over that's 2.80 effective final drive ratio so gas mileage should not be too bad even with 3.73's. The other thing you should do is get rid of the 2 piece rubber damped drive shaft and replace it with a single piece unit. I've been pleased with my conversion. It took a little fiddling with the vacuum switch to keep the converter clutch from hunting but after getting it tuned in (its adjustable) it has been great.
Hope this helps.
Jim