Re: cc heads
I,d look for another shop to do the work.You can certainly fit inserts with a 4v size ex valve. Forget about fitting the 4v intakes on the 2v heads. Standard size inlets are 2.04 which is plenty big and Ferrea make a stainless unit at around this size. this size valve will still move plenty of air for most purposes short of full on engines. If you must go bigger than stock then purchase a set of 4v valves and have them turned down to 2.1 as brenx suggested. Anything larger than that size usually suffer . you simply can,t get the short side radius to work properly with a 4v valve in a 2v head.