"Which T-5 are you using? I'm trying to help my son find one for his '66 Chevy 1/2 ton restomod, stock appearance but mild performance oriented sbc 350."
Chevy never put a T5 behind a motor bigger than 307 cubic inches. You might try researching other more dependable transmissions for a SBC powered vehicle. On the expensive side is the tremec transmission. For mor reasonable money you can get an my6/A833 4 speed with overdrive. The MY6 was a Dodge New Process transmission that found it's way into some chevy trucks. It will easily hold up to 400 hp/ 400 lbs torque. The same can not be said about a T5 transmission.
