can any of you other guys tell me if i can run 1.7 roller rockers with an e-cam on stock gt heads or do i have to use 1.6 for stock springs. also how much more lift does the 1.7's add to the cams lift & duration? thanks paul :help2
Not sure about the springs and running it in the stock heads. However the lift is multiplied by 1.7 instead of 1.6 thats the ratio of lift. The cam specs might be listed for 1.7 already a lot of them are. If just divide by 1.6 I would assume thats how its done and then multiply by 1.7 instead. Thats how it was explained to me.
lobe lift x rocker ratio: e-cam lobe lift is .311 x 1.6=.4976 valve lift x 1.7=.5287 valve lift i would definatly upgrade the springs before i ran the 1.7's
My car is living proof that you CAN run 1.7s on stock gt 40 heads. I did upgrade springs to be on the safe side.