TH350 to 200R4 Conversion

[Flbandit98]

Has anyone done this swap? I need some advice. I am planning on putting a 2004R in my 1979 TA with the Olds 403. I need to know what crossmember will work with this swap? Do I need to find a TH400 crossmember or can I just move mine back the six inches. Any advice on this swap would be greatly appreciated. Thanks

[Frosty]

You will need to upgrade your stock shifter to include a new dedent for the overdrive. A $100 kit from Shiftworks should do the trick, you can re-use the stock tranny cable and shifter to keep it stock appearing.

The TH350 and TH200-4R are the same length but the mounting location for the cross member for the 200-4R is 6 inches towards the rear, so you will need a special cross member. You can re-use your stock drive shaft though.

You will need a T.V. cable that you attach to throttle linkage and the transmission and a lock-up wiring harness kit for the lock-up torque converter. You may also need speedometer cable gears to keep your speedo accurate.

You can contact a company called Bowtie Overdrives. They have conversion kits for both 700R4s and 200-4Rs. Call them and ask them for advice. They also sell the parts I've mentioned. They sell a second gen Camaro cross member for the 200-4R, it should fit your Firebird, but you should verify it with them.

With the cross member moved back 6 inches, pay attention next to your exhaust and catalytic converter to insure there is no interference with them.

http://www.shiftworks.com/firebird68-81.htm

http://www.bowtieoverdrives.com/