Which hole do I put it in?

[Solver]

Got a 3/4 ton longhorn with th400 tranny and it originally had a 402.
Now I am putting it back together and using a 350 engine.
The tranny crossmember was in the midlle poisition of holes.
Do I need to move it(tranny crossmember) forward to the front holes for the 350 engine?If I do this will the drive shaft lenght still be ok or did they make a different driveshaft for the 350/400 combo compared to the 402/400 combo? Got the cab off so I can't use that as a reference. Will be using HEI so I don't want to be to tight on firewall. Also want the 350 fan shroud to line up right.
Thanks