New Driveline or Donor Driveline Shortened?

[BANKO]

Hey Guys, I am doing a Viper T56 swap into my 65 Chevelle. The car has a 10 bolt and 1310 u-joints. I need to swap the trans yoke to match the 30 spline Viper output shaft and I'm considering moving up to 1350 u-joints requiring a pinion yoke swap. Not sure if finding a donor driveline out of a 1/2 ton chevy truck (with 1350 u-joints) shortened for application is a good idea or if I should move up to custom Chromoly drive shaft. I am concerned about critical driveline speeds as I will be keeping a 3" shaft for tunnel clearance.