what would installing 1.6 rr on stock heads increase the total lift to? i would probably install at least lt4 springs as well. what should i expect out of this setup?

 

Take the stock lift of the cam in your car and divide by 1.5 then multiply the results by 1.6. That is your 1.6 ratio lift. LT4 springs will be plenty. You could pick up 10 rwhp with the new springs and rockers.... potentially more.

 

People usually swap out the vavle covers for LT4 style when going 1.6.

 

No, people usually clearance the valve cover supports on the stock covers so they don't interfere with the rockers. Those LT4 covers aren't cheap.
I did 1.6 Promags, 7/16 studs and LT4 springs. Made a noticeable difference. Worth it IMO.

 

if you go w/ gmpp 1.6 rr's you dont have to do anything to the valve covers. Direct bolt in. Gotta love gmpp.