Contrary to some beliefs, reprogramming a stock 496 other than raising the rpm rev-limiter will not have any noticible (speed of boat) change in power for the engine. If you are changing the valve train stability and quality of the 496 such as with our new aluminum heads you can safely raise the rev-limit of the engine to about 5400 rpms and gain boat speed with proper propping if your hull will use the increased efficiencies.
The only things that really raise power in a stock 496 are upgrades to the engine such as our kits or exhaust header or header manifold kits and supercharging which Raylar does not recommend on stock block 496's.
How do we know this, our years of dyno testing and in boat testing prove it over and over. Take my advise and save your hard earned dollars until you can make effective upgrades!
Best Regards,
Ray @ Raylar