Do tell......some of use are currently trying to make more power of these 496's.......any info would be appreciated.

I've got a couple of used HO cams if anyone is interested. If you can do the labor yourself, changing the cam and a Whipple reflash is a lot of bang for the buck. I've done a lot of them, and just about any other 496 mods you can think of. Dart has just released cast iron heads for the 496. Supposed to work really well. Tyler Crocket is testing them now.

Bob Lloyd
Full Throttle Marine

Bob,
How much for an HO cam? Would I have to change rockers, springs, or anything?
Thanks
Joe

Nope,just cam,reuse lifters because their roller lifters,reflash ecu,drill out idle bleed hole from 1/8 to 1/4 at throtle plate and you have a 496 mag HO,done that to my twin engine 30 foot powerquest,went from 73.9 to 80.2 gps speed.best bang for the buck

I'll take $200 for a cam. Just a pcm flash & drill out air bleed hole.

hi all can anyone tell me if my 496 ho would of had the aluminum exhaust the motors are 2001 ,but i only bought it last year and the guy replaced both sets of exhaust the ones on the boat now are iron ,did not buy the boat from owner so i can not ask him bought it from National/L in fl reading the above it sounds like some ex ports are better than others on the 496HO thanks paul

Best place to start is Bob Lloyd's Full Throttle Marine web site http://www.fullthrottlemarine.com/. Go to the "View Our High Performance Projects" and read the "496 Mag Dyno Testing & Myth Busting" article. I addition read the follow up information Bob posted on OSO, post #1 & #4 regarding the CMI Sport Tube headers: http://www.offshoreonly.com/forums/g...dyno-test.html

#1 To get unbiased straight skinny regarding 496 upgrades bang for the buck call Bob Lloyd. He is my go to guy for over six years now. He can give you the answer as to what you need to get the performance you want from the hull you are running and the best package for that. As power goes up additional upgrades in the drive and/or steering can also be necessary. #2 Any custom head or throttle body porting go straight to Jim Valako. #3 Any custom cams go straight to Bob Madera of Marine Kinetics or Raylar cams if you are keeping the stock heads and valve train. #4 Dana Torque Flow exhaust is the best bang for the buck on a 496. #5 If you want 525hp out of a 496 buy the Raylar kit and change to forged pistons.

Where can info on the new 496 Dart heads be found? Price?

On paper they are showing big gains. In real life many of us have seen absolutely no improvement on a 496 Magnum HO. Search it. I'm not the only one. I don't know where they get those numbers. A few people report 1 or 2 mph gain but I bet sometimes it is wishful thinking. Again, research real world results. Not numbers on paper.

This guy claims a 11 mph increase and he did bottom paint at the same time.....bottom paint on a Donzi Ragazza? http://www.offshoreonly.com/forums/1887205-post7.html

Anyone considering exhaust upgrades for the 496 should read this thread, starting with post #9. Save your money for something that will really work... http://www.offshoreonly.com/forums/g...bang-buck.html

Thanks for the info......