Get a set of "long-slot" rocker arms. The rockers are bottoming out on the studs before you get the adjustment right. That bends pushrods and breaks studs. The kids in my high school classes made that bonehead mistake on a regular basis. "Higher lift" does no good unless you do everything it takes to make it work. Bolting a bunch of mismatched parts together is not engine building. Now you're going to need to change all the studs since the ones that haven't broken already have been overstressed and they're going to break soon. Run- - - -do not walk away from whomever built that engine!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!