The Biggest problem I have with all the Mopar Procomp heads is the lack of ANY helicoils. This is a big problem for me and for this reason I wont use them. If you think about it, aluminum threads are not that strong, and when your dealing with CNC ported heads, your going after some HP, right? Well that means BIG cams with high spring rates. You have a better than good chance of pulling the threads right out of the rocker shaft hold downs. Plus striped threads on the exhaust and intake. No thanks. Sometimes cheap is just cheap, and Procomp is cheap.