I have a vortec combo right now that is running 12.6 at 110 at the track. The heads have been modified for .600 lift with 330lb springs and screw in studs. My cam is 290/306 duration with .510lift/.540 lift on the intake and exhaust respectively. Surprisingly i've found the ideal shift point to be ~6800 rpm. Swapping to 1.6 roller rockers from the stock stamped steel would yield .544 lift on the intake and .576 lift on the exhaust. From what i've read, stock casting vortecs intake flow peaks at around .480 lift. The exhaust flow hits a plateau. I know that I will see horse power increase from the reduced friction. My question is will eclipsing the threshold of the intake flow diminish any hp gains? Something to take into consideration is that with more valve lift, the valve will stay open longer allowing more air to enter the combustion chamber, but will the decreasing flow past this threshold even net any extra air? Would I see a low of low-end torque and a slight increase on the topend?

 

If you do go to a 1.6 rocker, dont forget to enlongate the pushrod slot in the head with a 1/2 inch drill bit to keep from bending the crap out of your pushrods.

 

I suspect you won't notice much of anything from changing rocker arms, either from the ratio, or the roller aspect. If anything, the increase on the exhaust will be more beneficial than the intake side.

 

need help can i put a noisy gear drive in my 1991 rs camaro if anyone has done this before can you guys let me know what to do thanks