hey guys, im soon to be doing the cam and spray in my sig and have an opportunity to pick up a set of stock 5.3 heads....do you think i would see any gains with just throwing the heads on as they are and not having them ported or anything? any help is appreciated! thanks!

 

leave your stock heads the valves are soo small and the flow is close to ls1 but not ls1 flow trust me dont do it the tiny gain in compression wont be better then your bigger valved better flowing ls1's

 

Whats the casting number on the stock heads your running now?

 

853 and the 5.3s are 862 irc