4 speed trans to Th350 driveshaft question

[rcranger]

have a 64 that converting to auto, have the right cross member for the auto, have searched and searched but can not find a straight answer, the truck has 2 piece shaft want to keep that or try,do i need a different shaft for the one to the carrier bearing or just need a slip yoke for the trans and this shaft will work,seems like a simple question ,or does that shaft need to be shortened