There are always pros and cons to any project but it all comes down to budget vs your goals. If your looking to just bolt on power, superchargers are the best way. However, if you are willing to pull the engines tare them down and have them completely rebuilt, internal mods are the best way because you can tweak those 500s to push over 600hp. If you do decide to do any internal work, I know a buddy that owns a shop in Cleveland. Gellner Engineering was recognized as a "top notch" engine builder in Powerboat magazine and has been well known in the boating and auto racing world. Call Dean at 216-398-8500 tell him PK told you to call. He can also give you more information about getting more power out of those 500s. He tweaked my 454 from 385hp over to 550hp N/A!!!

SMoooch

Ill trade ya for them 500 efis. if thay have low hrs. 540 ci 950 hp.420 mega blowers with chillers bowtie blocks all good stuff. to much for a 30 ft boat. I took in on trade looking for some 500 efis. I was going to detune them if I didnt trade them off.

Your hooked !!

http://www.offshoreonly.com/forums/a...1&d=1190416649

engine shot of my ol' 1996 Gun
Still running great for it's current owner.

I Whippled mine this spring. I love the package, and it looks the best IMHO. Loads of power!

That's the set up !!! :D Very nice and clean.

Damn it Otis, I am hooked...... and now shopping :D:D

I put a vortech on my EFI 500 after 60 hours. It now has 240 hours and the only problems I've had is two broken drives. Comprestion is still good in all eight.

Tanner..... The way I've seen your 98 Cig run you need to take those engines out & put them in a twin step.
I would think you would be over 100 mph.

LS

I whippled my 500,s and I'am very happy with the power and durability. But you will have to go to bigger props or taller gearing to see the gains you want for the money. Expect to have some drive failures.