Nothing wrong with that 3-speed that making sure the shift linkage is decent won't cure.
(Hey, how's that for syntax?)
Chevy 3-speeds have been in zillions of cars, trucks, etc. make sure the two little steel actuator gizmos inside the tranny aren't worn - just pull the side plate and look; and then tighten up or replace the shift linkage.
On the 235, have you verified that it's a pressure oiler? There are 235 babbit motors out there.
LBNL, with a good 235 there's nothing wrong with 4.11 gears; it'll pull better.
Cheers!
George
