Originally Posted by
Billy_RS
I've read that you want the c20let with the 'coscast' head? Cosworth head that has a thick wall between oil and water jackets?
Yours looked a lovely car mate btw
Ideally yes coscast head is the one to try and get. The problem that c20xe +let engine have a weak spot on the water channel and you end up with yellow Mayo cooling system, not all gm heads do this and once modified it will be fine you can get the diy sleeve kit, straight forward to do but most have had it done by now. CTOR forum is the place to have a butchers at.