Need to put power in a 2003 31 sonic, it was built from the factory with 575 supercharged motors bought the boat without engines, in 03 most came out of the factory with 496s, so my question is this, would it be easier to put in 502 mags since it had 575sc and I believe everything is the same and will line up with the exhaust holes on the transom, the race engine mounts, or my other option is to go with the 496s but I believe that the mounts are different, possibly the angle of the exhaust, etc., as far as speed I think the boat should run about the same with either engine package,any input guys?

Thanks

Mounts are the same for 496 vs 502, exhaust is very slightly different but most 502/Bravo boats can go to 496/Bravo without significant exhaust changes. Speed should be close, possibly slightly faster with the 496s if we're talking totally stock for both.

500 EFIs are pretty much same motor as 575sci minus blowers, so all should work together.

Except for whatever reason HP500 EFI's were full roller motors.

Maybe there wasn't clearance under the 575 intake/blower for the spider that secures the lifter dogbones?

You better verify the 496 has the same plug in for the electrical harness. That could be an obstacle to overcome.

so is a 500efi block the same as a 502efi block?

thought of that as well, thats why I am leanings towards the 502efi,thanks

Yes, same bottom end. Different cam, valves, valvesprings, and of course intake/fuel system

they are all 502 cu in, hp 500, 500 efi 525, 600 and 700..black motors go by cu in and the blue ones go by HP