need help with engine

[Phillip123]

I have just acquired my grandfathers 63 C10 p/u. it is a stepside short bed in very rough shape. The cab is in pretty bad shape on roof and other usual places. I will get back to the body work later. I have pulled the engine out (283 ci) and pretty much disassembled. I am no mechanic by any means but have some basic knowledge of how a engine works. The truck has been setting in the bushes for about 15 or more years. It appears to have had a blown head gasket. My son is in his first year at a community college takeing auto mechanics and has torn down the heads, most of the valves have been burnt. With all that being said here is my question, I would like to step the engine up a little but not sure what size cam to put in it without having to change lifters, studs, springs, etc. Im thinking of boring it 4 over. Not looking to make a hot rod , just want a little punch to it. Staying with stock 3 speed and rear end I think. Any advice and guidance would be appreciated.

Thanks