I think it has alot to do with the whole setup. Basically how well everything breathes. I had a few guys tell me that it might run better with the stock ratio rockers. Or at least on the intakes because I'm running a cam with so much overlap.(I think that's why) Probably not worth the trouble on a stock motor.
Stock cams were pretty low lift given the duration. They also don't have much overlap when compared to aftermarket grinds. So if it's true that for a tight LSA it's not a good choice, then for a factory cam it should be a great one.
I've never seen dyno numbers where the only thing changed was the rockers. So no data to say it's good or bad. But how many do actually change just that and then evaluate the power? And if they do, did they do tuning adjustments to compensate and optimize?
Jim Hand seems to love larger rocker arms and he's running a station wagon in mid-11s with 3.42 gears, full exhaust, ported factory heads, modified factory non-H.O. intake, factory spec. cam (although this varies), and a 850 Qjet. So I tend to think he knows what he's doing.
