.750 lift roller cam with a 1.5 rocker.
Cams with that much lift using 1.5 rockers usually have quite a bit of duration.
Any other cam specs you can share?
I’d get a few more laps on it, hopefully at wot for the entire 1/4 mile, before I thought about changing anything significant.
Along with that it would be a good idea to go over every possible rpm limiting problem that might exist. Start with valve springs. How much seat pressure and over the nose pressure do you have, and does it match the lobe profile you have? Fuel delivery OK? Ignition good enough? Sometimes rev limiters start dropping cylinders too early for the rpm selected. A 500 inch 440-1 headed motor with a .750 lift 1.5 rocker setup would have at least 276 @ .050 intake duration and probably more like 282+! With a well sorted out motor i would expext power to peak at 7,000 to 7200 rpm with torque peaking about 5400. It should easily pull to 7200 or a bit more.
