'68 Dart with a 318 LA - Build Options
One thing I ran into with the 302 heads was the air injection on the #7 cylinder hitting the exhaust manifold. I rebuilt a 1987 318 for my ‘65 barracuda thinking it was a direct bolt in. When I started it I realized that the air injection boss was hitting the exhaust manifold where it returned towards the head to clear the steering shaft. I got it ground down to clear finally. You need to make sure you use the correct exhaust gaskets being the ones for the 302 heads have a larger opening than the nonsmog gaskets do. The larger opening creates a exhaust leak when you grind away the air injection boss that would normally back the gasket when the exh. manifold bolts up. That was the only hang up I encountered.
I bored the motor .030 over, put in flat top pistons reversed, a mild summit racing cam, Edelbrock performer intake and a Edelbrock 650 carburetor. I’m still running the dual point distributor. It has plenty of power and runs great.