This is the area that needs to be ported out for the S/T manifold and 36 DCD carb, the head is pretty thin in this area so cutting it with a die grinder and cutting bit should be pretty easy, I will leave the head on and stuff it with shop towels to catch the grinded bits then vaccum it out and reinstall the head bolts.
I will mount this manifold and carb to the 600 shortly, the intake hole will have to be ported to match the Scuderia Topolino manifold. Paul a S/T recommended jetting and 25mm chokes which I sourced from Pierce Manifold in California. The go to place for all things Weber.
