I had my '66 one piece shortened. Installed a new front yoke & u-joints. I'm comfortable with it, but ,of course, time will tell. It's not like we'll be drag racing these trucks. My mild 454 probably has about the same torque as your 383 but less HP.
1966 C-10 Short Stepside HiPo Step-by-step ~ and on-going resto build in the Project Journals
