Gavin,
What 235 are you running? The 54-62 or the splash oiled variety?
What do you want to do with this truck?
If the engine is already out of the truck and is a full oiler 54-62 235, I would buy a book or two and give rebuilding a try. The machine shop will do your block and head work. But all of the parts and work will still cost you some money.
As far as the tranny goes, if you are building a daily driver, drop in a GM T-5 out of an S-10 and a different rear end and increase the speed of your ride. If you are going for stock, you could try a tranny shop to take a peak inside to see how your gear box looks.....
Lots of options depending on what you want to spend. If you have the $$ someone out there can do almost anything you want....
