The standard 8 valve inlet manifold stands very high over the rocker cover and I am wondering whether to save space the inlet manifold from a dohc 16 valve RS cylinder head (which appears much lower!) will fit the 8 valve head?? In more simple terms, can anyone advise me please whether or not the manifolds are interchangeable???? If they are I'll be looking for a 16 valve manifold.

 

Manifolds are very different as the 16 valve head has oval ports, 8 valve ports are almost square.

 

Thank you very much for that clear and helpful answer. There is no hurry at present so it's back to the drawing board!