ive read that the intakes and injection systems are better on the blue 500hp motors than on the black 415 hp motors,but how much better?enough better that they are worth the price stock without modifying?thinking of building a pair of 540 to 572s and want to stay fuel injected.

The 500 efi manifold wont make much over 525 hp without remapping the ecm and larger injectors, I don't know if I really understand your question

He wants to know if buying a blue take off setup is worth it and capable of meeting his goals vs a complete aftermarket setup.

IMO, speaking from experience the 500 EFI manifold will shut off at about 625hp because it will not flow any more air, if the OP is fine with that then its ok,

thats what im wanting to know,thanks.was hoping some of these marine engine builders have dynoed something close to this and will chime in.not looking for mega hp just something reliable that runs good.

Mine were built by one of the best in the industry, so I guess he is chiming in.

ok...so you have the efi intakes with no power adders?what kind of power did they make?what head did you use?

540 cu in 630hp 660 tq @ 5400 rpm AFR 305 heads custom grind cam, stock 500 efi intake with 65lbs injectors

I think 625 is really pushing it thru that intake.

hummmm...thanks 33outlaw