Magnum head and exh manifold ID

And a correction to you DGC333, you can use LA "Aluminum" valve covers on a magnum head. You cannot use a stock steel valve cover from an LA because they won't clear the rockers. Other than that all your other statements are dead on. All I need for my conversion from my stock 360 heads to the magnum heads on the floor in my garage, is an intake. :evil: