The boat I just bought has a 496" 420 mega blower, 8.7-1 compression . The cam is a hyd flat tappet, 240 246 .560 .570 with a 112lsa. Does that sound like a good cam for this setup? Motor made 720hp 697 TQ on 6 psi.

You've already got a Bravo drive buster.
There is always something better, so get ready for a 100 choices.

Like mentioned there are a bunch of options but I'd pm mild thunder and see what cam he is running. He's running same blowers on 468's with eq heads making 800hp. Your 496 should make all of that with the right cam and head combo. Depending on hours on current engine I would suggest wait for rebuild/refresh time to make any changes.

I'd go with a 2/3 race cam. I don't think you have enough compression for a 3/4 race. Make sure it has the 2-3, 4-7 swap so it doesn't sound to powerful and get the attention of the H2O Po-Po.

Thanks guys, only reason I asked is because it does surge. Afr is 13.5 at idle 12.4 at I believe (don't have sheet in front of me) at 4000rpm and 11.7 5700 to 6000. Oh and motor has 3 hours.

or maybe a 3/4 race cam with a reverse firing order,i hear that is the new hot setup.

what carbs are you using.

I haven't heard 3/4 race cam since the sixties. and I am pretty sure it was meaningless then. I am assuming there was some tongue-in-cheek there?

Mike, It has twin Holley 750's

http://www.enginelabs.com/engine-tec...race-camshaft/.