Here is where the intake manifold came from. An Offenhauser 3X1 for a 230-292 Chevy 6 The 153 ChevyII four is 2/3 of a 230 Chevy six. A table saw with a carbide tipped blade Two cuts Get rid of the extra 1/3. TIG it back together Add a plate and fittings for water heat. Done!