I need some help! I have a SBC in my 64 SWB Chevy truck and currently run a turbo 400 trany but want to change to a 700R4. I have the 700R4 ready to go in but the old drive shaft is too long since the R4 is about 2.5" longer than the 400.

Anybody out there know what donor vehicle drive shaft will work so I can install the 700R4 behind the SBC on my SWB 1964 Chevy truck? I can have mine cut and rebalanced but I'm moving soon and hoped to keep it simple.

Please respond to my email address if possible and soon! I appreciate any help!! THANKS