Whipple makes a complete kit that will bolt on. It includes everything you need plus reprogramming of the PCM. With that said, no one can tell you how long the pistons will hold up. They are the weak link. The 496 pistons are weaker than cast 454 pistons. The reason being is they were designed with a very high top ring land to help with emissions(as I understand it). That leaves them weak when subjected to higher than normal loads. I just rebuilt 2 Whipplecharged 496's, upgrading them to forged internals. My recommendation would be to upgrade the pistons and then add the whipple. Tyler Crockett sells some forged factory replacement pistons made by Diamond. Use them and keep the rpm below 5400 and it should live ok. The engines I just rebuilt had been running for 2 years before a piston failed. They had maybe 60-70 hrs on them.

Bob Lloyd
Full Throttle Marine

The problem is not with the internals it is with the setup of the internal for n/a. Yes the top ring is set high on the hyper pistons. For these to work in a blower app you must open the compression ring end gaps a lot. If you don't they will butt and it will lift the ring land. This of course is not a piston failure but a setup failure. Beyond ring gaps, you need better head gaskets, head studs, better fuel management to ensure rich a/f and less timing. What would stop me from supercharging a 496ho is the ring end gaps and computer. Put on a carb/tbolt ignition and open the ring gaps and a few other odds and ends and it will run great for as long as a forged assembly.

Blower motors
 

You can ask around until you find someone to tell you they have put a blower on a 496 and it hasn't blow up-yet. But that will not stop it from coming apart. I have been running superchargers on boats since the mid 80's and have blown up a few engines and melted a few pistons along the way. You should see the wall of broken parts I have accumulated over the years and the one thing I can guarantee is, the better the parts you start with, the longer and more trouble free your project will be. Blowers are not magic, they just increase the volumetric efficiency of a motor and make it burn more gas, thus make more hp by forcing more air/fuel mixture in a cylinder before the spark plug lights it off. If you want to put a blower on a stock motor and turn the boost way down and not run it hard, it will last a little while. But if you spend the money on a supercharger to go fast and then you baby it, you are a better man than I. I have extreme motors and boats because I like to run the crap out of them. If you don't, why have a blower? For looks? I know it seems easy and cheap to just bolt a Whipple on your engine, but most likely you will not be happy with the results. You can sell your 496 for 6K to 8K if it is in good shape and put a 454 in there with good parts, (not top of the line but good) that will be a much more dependable motor that you can actually use normally and make 650hp.

Attachment 440237

Attachment 440238
One of the first boats I supercharged

Whenever anyone asks about mod-ing a stock engine, this disclaimer should automatically pop up. This is the best advice you can give someone asking this question. Period.
Eddie