I'd skip past the t5.. you'll break it.. g.m. didn't put them behind 350's for a reason..
torque is that reason..
a t56 or a tremic..
most shifters are to short, so you'll be fab'n up a longer one, and can bend it. to get it in the correct spot for your hand..lol
my dads 84 f-250 stick had a "s" in the shifter handle shaft.. that got the shifter towards the driver..
only way I'd put a t5 behind a 350, is if I knew I'd never get on it..
ft lb's(torque) and a heavy truck will not be kind to it..