Originally Posted by fast68plymouth
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I had my revlimiter set at 6300, plan to bump that to 6500 or high next time out, it was either starting to bounce off of it or float valves around the 1000-1100 ft mark.


If it’s some type of hyd cam, it’s certainly possible(and not uncommon) to experience valvetrain control issues before ever getting to 6300.

I usually sneak up on the rpm on the dyno to see if I can determine where the problem starts........ then you know.



It’s a .508/292 Mopar purpleshaft cam,with Smith Bros push rods, Harland Sharp 1.5 rockers, I feel like the week point might be the valve springs themselves, it has whatever Areohead (Indy cyl head) installed on them, they were supposed to be good to .509 lift. We were only pulling it to 6000rpm on the dyno and never went past that.