Are these billet units and fully customizable or are they machined off of blanks? I'm interested in one if you can change the firing order.
I would be interested as well. My motor is completely stock and the heads were redone with hardened valve seats and a three angle valve job. The bottom half has never been apart in 85k miles. So if I wanted to put in the roller cam and lifters, along with roller rockers, would I or should I need to do anything to the bottom 1/2? Do I need to replace valve springs with better ones? I do not know what the cam profile would be but what kind of power gains would I see on a stock set up by modifying it with the above parts? Thanks for taking the initiative on this Mike!
