Ok yes, I guess to clarify, my 1990 350, I want to put on aluminum aftermarket heads on it, that are listed as 1955-1986 sbc 350. Will I be able to bolt these on without issues? I know the manifold will be different
I believe you are asking about the compatibility between first gen engines and vortec headed engines. If you use heads for a first gen small block the older heads will bolt on fine and you can use intakes for first gen engines. If the heads you buy are on the vortec platform you will still be able to bolt them on earlier model first gen blocks but will have to run a vortec style intake. It will all depend on the heads you put on your engine. One easy way to tell is that the earlier head designs have four bolts on the outer rim of the valve cover to hold them down. Vortec style heads will have the bolts in the center of the valve covers in a line to hold the valve covers down. There is a difference in the way the intakes bolt on. The older first gen small blocks will have the intake bolts going in at a angle and the vortec intakes will have the bolts going almost straight up and down.