Im not sure on the rods. But I do know the GMC's back then, even though they shared the same cabs, they were a lot different than a chevy. they had their own engine, which was a Pontiac design,& the frame on GMC was heavier than a chevy.
Go to the Links page of this site and check out Old GMC Trucks .com. there is a lot ofinfo on the GMC's there.
Last edited by JeffL; 08/22/2009 1:18 AM.
