Head gaskets & pistons will have to be specific to all 305 engine from 1960-74, intake and exhaust manifold gasket are the same for all 351C, 379 as well as the non Magnum 401 and 478 engines manufactured up to 1965. Oil pumps are interchangeable with all GMC truck V6 engines regardless of cubic inches, same goes for rod & main bearings with the exception of 73-74 478M engines as these engines have considerably larger mains. The 351 was discontinued in 1972 and replaced with the 379 for 74-74, basically a 351 with the 478's stroke.
