well the 500 efi's are 502 ci...just 500 hp not the 415 like the mag....the 500 engine are the way to go!....hard to beat them for reliability!

Those Motors are fine Quiet storm. Some people call them EFI's but there MPI's. The internals are the same as the 500, but with a different exhaust, cam and Intake.The 500 Leaves you with 470 HP. rather than 415.
have fun

415 is at the crank as is the 500....and the internals are different!!!!!

Not looking for an argument Audacity, But I have the Mercury Mercruiser book in front of me and the 415 is PROP SHAFT HP!!!!
The 500 is 470 Propshaft HP here's the link502 mag MPI spec

here's the 500
500 efi specs
I also agree that the internals are a little different, but they both use good internals
Happy boating

you are 110% correct...thanks for making me re-think that!

I've done that more than once or twice
I usually blame it on my typing fingers.

Thanks for the input guys. From all of this I think I would not be going wrong with this boat. The 502 mags could take more HP and I would use Whipples to get it. The 500 EFI is a stronger motor but the boat that I'm interested in doesn't have them. So, someday when I can afford more HP, I will be confident that I can add it without loosing reliability. Also, if I add more HP to the motors I should look at strenghtening or replacing the drives.

Hey Joey,
Why don't you sell that Active Thunder and buy my Supercharged Checkmate. I'm ready to make a deal.

ok,,,lets talk.

I have almost 100 hours on a Whipplecharged stock 502 Mag MPI in a 2000 Velocity 280 ... it works beautifully. I turn a Bravo 1 30". I also have the larger 2100cfm throttlebody from Whipple. I have had no engine or outdrive problems. It's a stock Bravo 1 outdrive except for a drive shower (Gaffrig Innercooler).

I noticed the cat already had 30" Bravos ... you may need to go to 1.36 which will put more stress on the outdrives. 34"s would be tough to turn and inefficient.

Good luck

wilerty

I needed to hear that someone had good experience with Whipples on the 502 MAG MPI's. They are great on my 454 MAG's but they have 750 Holleys. I wasn't sure how well the Whipples worked with MPI's.

I hope to take a ride in this boat tomarrow and I just might find that 95 MPH is fast enough or untill I get passed Then I would go with the Whipples.