Just found out that a procharger won't fit on my 496ho, because theres no room, but the dealer will put in a new hp500efi with edelbrock heads for $3000.00 cdn. more than the procharger setup, with my trade, he says it will give me 500hp at the prop.Do you guys think it will give me the 5 to 10 mph Im looking for.

Dunno but a Merc EFI 500 is rated at 470HP at the prop, the 525sc is rated at 490. Your 496 HO is rated at 425 at the prop and some say it is a conservative estimate. So I am going to say no you won't see 10 and I doubt you will see 5 with a 45HP gain. If it does make 500 at the prop you might see 5 but it will depend a lot on your hull. Maybe with that motor and a lab fisished prop you can get the 5 maybe a little more.

Try the 496HO with the NEW Whipple that should be ready now. That set up should fit in your boat.

The new HP 500 with the alu. heads[rated 500 at prop] is much the better engine.I doubt your dealer will do that for 3000 difference.If he will I would go for it,you can procharge it.That engine has all the good parts. Doug

It will acually cost $12,000,00 cdn.difference.The boat is a campion chase 800, it does 70 mph want at lease 75 mph if Im going to spend the money.

Hmmm... I might be wrong on this but the 525 EFI is 500 at the prop but I believe the 500 efi is still 470. 2 different motors.

The difference between 500efi and the 525efi is that the later has aluminum heads and has a close cooling system.