My understanding of the 20r & 22r is the differance is the piston size.I have a 79 20r and instead of finding a 22r block to mate to my head can I just bore the block out to be a 22r or do I need to find one

 

Can't say I'm an expert, I'm just on my first build myself. I wrecked my 84 pickup and in an angry fit basically gutted it. decided to rebuild the motor (was told it was 22r, it was a transplant 20, should've known better thought I could trust the guy). Anyway took the block to the machine shop and the guy there punched it out .30 and said he'd done it on another toy and with can headers and a weber he could roast all 4 tires. Haven't got mine up and running yet so can't confirm his claims but hope this helps. If not 22r blocks seem to be plentiful and cheap. Good luck and hopefully someone who actually knows something will answer sokn