man. . . .starting to get my hopes up here and there because i think i might be able to tell what motor it is. lol. im going to try and get the bottom end without pulling the motor. granted it would be much easier, but i dont have a hoist- nor do i know anyone around with one. and i have a feeling im going to need to save as much as possible for gas to and from the store for having the wrong parts! why would any one make several different sizes of motor with totally interchangeable parts? stupid chevy. . . .god i love this truck! hopefully by this weekend i will have gotten the heads off and can see the casting numbers!