Very nice boat. When I called Indmar to determine if I had an HO 454 or standard 454 here is what they told me. " If the 454 has an aluminum intake manifold it is an HO454 around 400 hp if not it is a standard 454." Both manifolds are painted black. Should be able to check it with a magnet. Here is the parts maual. You can see different part # for pistons, cam, heads etc.