Thanks for the replys, guys. I was thinking the .471 was about right for what I had in mind, been a few years since I built a performance motor. I'm a firm beliver in low cost parts, new or used. Why pay for a name when a gereric will do?
Care to elaborate? I haven't run into or read about this yet, and I don't want to run into it after I put it all together. It is just limited to pedestal rockers or all? Odds are I'll have new rockers anyway rather than use the cast rockers on my 351 donor heads, but I want to understand.
The slots in your rocker arms are only so long. This goes for any stock rocker that is stud or fulcrum mounted. The stud goes through the slot. The rocker goes up and down, and the slot clears the stud or bolt. If you add lift, the rocker travels further and uses more of the slot. After a certain point, the slot is not long enough to clear the stud or bolt. At this point the rocker makes solid contact while the cam is still pushing upward. If you are lucky, you have push in studs and just pull the studs from the head. If you have aluminum pedastals, you can gall the aluminum into your oil or wipe the cam. Aluminum pedastals are notorious for galling without help from a high lift cam. If you have iron pedastals, you will surely wipe the cam. Roller rockers already have enough motion built in. Some aftermarket rockers are labeled "long slot" or "extra long slot". Chevy 1.6 long slots work fine if you have adjustable studs and plates. Dave
