The SM's or KE's will make about the same power as a set of CMI's. The Gils will start choking it at 575-600hp on an NA engine.

You could try contacting axapowell on here. He has a '98 353, had 500's that he upgraded, then added boxes, XR's, and shorties. Don't recall all the specifics of his build but he might share with a fellow Formula guy. If I remember corectly he ran right around the 80 mark with the stock 500's minus the boxes and shorties. Believe he has stated 97 now, he could tell you details better than I. Think he ended up around 650 fully rigged with the CMI E-tops on the dyno, and 700+ with dry dyno headders.

Thanks, I talked to a few of these fellows and got some good advice on the the possible directions we could take. Definitly need to think over the super chargers.

I was waiting for the punch line.....500's no blowers ??? NFW..

650 is possible with AFR 315 heads and a good exhaust system. No way the Merlins will do it. If you need iron heads, Jim V. can make Dart Iron Eagles flow 400/300 at .700 lift. Then add a custom cam and turn 6000 rpm. Or use a blower.

Not so sure you need 650hp to get to 90friend of mine has an 05 353 with 525's xr standoff boxes shorties and 5 blades He sees 87mph in optimal conditions and 83 84 everyday he is loaded up with every option + generator.

Jeff wagoner did alot with a similar build-http://www.offshoreonly.com/forums/general-q/88806-cam-help-502-afr-305cc-heads.html

It's basically down to things, in no particular order:

- Engine builder who doesn't like blowers
- Wife killing me when she sees the bill for 2 blowers

Hey what wrong with the Merlins - my builder swears by them?

:argue:

Posted on the other thread
 

Posted on general discussion thread.

Joe
I did a similar build with my 382 Fastech and went from 73 mph to 83 mph, so don't get discouraged when they you can't pick up ten mph.
My stock HP500's also pulled 530 HP on the dyno with no choke horns and thinned throttle shafts. These motors were still in good shape.
I only changed the heads, cam and built custom carb spacers was able to get 620 HP in full marine trim.
I used the 305 cc AFR heads with cnc chambers and a mild cam.
Contact me if you need carb spacers or if you need water cooled billet top caps for your bravo's.

I hope this helps.

Jeff Wagner
Wags Engineering