I opted to rebuild a junkyard 200-4R when I did mine using a rebuild kit off of ebay (oregonperformancetransmission, iirc). Of course it is an otherwise stock OHC Sprint car, so I didn't need to worry about beating on it too severely.

Anyway, the fluid lines and driveshaft did not have to change at all for me. This car came with the ST-300 and later had a TH-350, all with the same driveshaft, etc. A TH-400 crossmember was required for the 200-4R.