If you are talking about spacers between your cast iron exhaust manifold and top cast iron elbow, then I had the same system in a 1987 Sea Ray Pachanga. They did make different heights (2", 4", 6", etc.). I purchased all mine from Palmer Power in Houston 713-644-6410. I will say though, that I lost a few engines when I tried to make the manifold system last longer that I should. Gasket surfaces would warp, I would add sealant, leak would eventually occur, and no more motor.