Drivetrain swap.1972 to 2001

[terry b]

Hi everyone. I have a 1972 C-20 with leaf spring rear end and a factory 402 with a turbo 400. I want to remove the L-31 vortex 350 and 4l80 transmission and disc brakes rear end out of the 2001 3500 express van I bought from our church and put them in my truck. Low miles and well taken care of!! Has anyone ever tried this combination? Will I need to change motor mounts? Can I use the one piece drive shaft? Want to keep the fuel injection and factory computer. Please help me out if you can. Thanks Terry.