454 mag upgrades?????

obsessioncatsass · 10-10-2005, 10:15 PM

I have a sets of 454 mag 385 hp efi moters in a 28ft catermaran. Im looking at putting a set of aluminum heads and a set of good manifolds or headers. What will I need to do with the fuel injection, or should I go carburated instead? Looking to pick up some decent hp gains. My boat also has 1.36 ratio bravo drives, could i pick up some speed going to 1.50 ratio drives? it spins 23 pitch 4 blade hydromotive props at 4850 rpm. boat runs 78 mph now. Any recommendations on what to put on it heads, headers, etc??????

lowflyin · 10-10-2005, 10:28 PM

Some will tell you to go to a carb, others will tell you to send the ECU out to Arizona Speed or another comparable shop that can reprogram it for your modifications. Arizona charged me 350.00 and I had it back pretty quick. Unless you're going to a wicked cam or really high HP I'd just stick with the injection.

SkiDoc · 10-11-2005, 07:03 AM

Tyler Crockett put together a package for me GenVI 454 mag carb, kept healthy bottom end, Brodix Al. custom CNC heads, roller cams, 177 blowers, MSD ignition, custom carbs, he claims 600/650 HP. The motors are awesome idle better than stock. Are so smooth would think are injected. I didn't dyno so I can't verify the HP but my speed gains would indicate this type of HP. My boat is the 97(older heavier hull)28 Daytona twin. Still working with props, but went from 73 GPS to 96 GPS. I would give him a call, he put the right components together for me, sold it for as good a price as I could find. He set the dist. and the carbs. Not simple but just put together and excellent result. He can rework the stock heads and save a bunch of money instead of the Al. ones.