buddy just built pair of 575 hp 502 on dyno with stock holley 800 carbs what woulkd be a good jetting set up was thinking 88 and 92 wants to be fat not lean of course and he is running 5300 rpms with timing at 38. What do you think.

Didnt they jet it on the dyno? 38* seems like alot of advance. I might feel better at 34-or 36*

I agree with 34-36 max. You won't see much gain in a boat with the extra 2 degrees...plus you'll be safe if you get any questionable fuel.

If you have no PV's, I would say you are real close/safe. If you have PV's, I think you are really rich.

He was just running 42 on timing and lost a valve and i also have 600hp blue motors run mine at 36 with no problems. Thanks Guys

You have no problems BECAUSE you run yours at 36*.

Agree i told him 36!!! but everyone always trying to get 1 mph more but not worth the consequences.

Do you have any details on his build getting 575 hp out of n/a 502's with stock 800 Holleys. Sound like healthy motors....thanks, Rick

problem found. valve guides were to tight.

502's 850 holley's, 580 hp @ 5400 rpm 610 ft lbs trq. 84 and 90 in the carbs now . 86 and 92 on the dyno. we are putting them back in. at 36 on the timming. thanks for the help guys.

42 on timing ?????? not even with 116 octane i would do that !