What is the most duration/lift that I can run in my 502 with 9:00 to1:00 compression.
I have lightning headers (restricted water flow), Dart intake, 830cfm Holley, heads have been mildly ported, three angle valve job and larger 2.25 valves on the intake. I am running a Comp roller cam 226/234 with .591/.601 lift on 112lsa installed at 110ILCL. The motor maxes out just over 5100 rpm. I am looking for a little more power on the top end extra 200 rpm.

DanB, has a 509 inch engine and he uses that Crane hyd roller cam #139741 on 112* lobes and it dyno'd out at about 565hp @5500-5600rpm. He's using World Products heads (308cc runners) non ported, a 950cfm carb (which I don't think you'll need---the 830 you have sounds fine) and he's using Lightening headers as well. Hope that helps

Tom,

BTW, I certainly don't think I would go with any larger of a cam than what I have posted. Perhaps some else can chime in on a cam that has worked well for them that is a little larger than the one you have now that they're using on a 502 inch engine.

I had a 502 Mag in my last boat with the following cam on a stock bottom end, stock (Reworked) Iron heads (2.25/1.88), Gil exhaust, dart intake, 1050 Dominator. No reversion or piston to valve clearence problems. Comp SOLID roller 252/258 @.050 on 114 CL .680/.708 lift, proped to turn 5600. I would stay with an 850 carb for better drivability.