sorry for the long delay to get back to you all i have been pulling doubles all week to pay for engine, the only numbers i have at this point are the heads # 6272992 looked at them before i had taken them off. I will get the block# hopefully tomorrow, because of all the doubles they a closed when i get off and when I go to work. They already started on the machine work on the block and crank so at this point going to keep those, My father already had the heads worked on. budget right now looking like a $1000 to $2000. Machine work cost me $300. just want a little bit more power without loosing an arm and leg. down the road I will buy a block and build it from ground up but first need to save money for that, and get this truck at least depandable with a little more power, after i do that then i got to pull the engine out of my 300zx twin turbo to do some repairs as well and that is going to cost me alot. again thank you all for the advice and tips. Just trying to figure out what path I want to take, And I just do not know all the good parts for these old chevy's. But i do know my motorcycles, and more upto date vehicles