I have a 2006 350 Magnum EFI engine. I am looking for a little more HP out of it. I was thinking of a cam shaft swap, but I think it has the 555 ECM and from what I hear the code on it has not been cracked yet. What are my options?

Good question... I have 2006 6.2s and unless you really tear into the engine there is nothing to do. Do you have the vortex heads? I'm betting our engines are the same except for the longer stroke of the 6.2. If so, the heads don't flow much above the stock cam's lift, about .480. The valve guides interfere with higher lift so there goes high-ratio rocker arms (unless you go to beehive springs and retainers - a lot of $ to spend, springs, retainers, rockers to get what, 10 h.p.?). The intake is a bottleneck. There are several tunnelram intakes out there that also need a larger throttlebody. RHS makes an iron head that Mercury used on their Scorpion 383 that they remanufactured. 400-425 h.p. Crane makes a neat little roller cam with a few degrees increase in duration but quite a bit more lift (if you are willing to change heads). I figured if I did all my own work I would have about $2500 per engine in parts plus the cost of retuning the computer to get about 80 h.p. It would be another 3k for CMI headers that would probably make about 420 h.p. in the 6.2 or 400 in your 350. A Whipple blower with headers, h-beam rods, forged pistons could be done for about 12k, again if you do your own work. Whipple is claiming about a 150 h.p. increase but that puts the power at a level that would be pretty tough on a Bravo drive... I'd love to hear what you decide and how it turns out. 80 horsepower would get you about 4 more m.p.h. If you don't already have an oil cooler you will need one, or a bigger one if you do have one. Also the oil pans are a bit on the small side.

Wes is right on the mark with his post. I've been down the same road. If you want a reliable bump in horse power you should seriously consider pulling the existing 350, sell it for what you can get and put the money toward buying and installing a bigger horsepower, factory engine. A new, factory-rebuilt, drop in engine simplifies a lot of other work. In the long run a new engine will be more reliable and end up costing not much more than hopping up the current block.

Here is my situation. 2 boats.
Boat 1: 1974 formula F-18 that was completely redone in 2006. New upholstery, gauges, paint , Corsa captains call and a brand new 2006 350 mag efi/alpha. The engine has about 250 hrs on it. Trying to sell the boat, but no one wants to pay $8000 for a completely redone turn key boat.

Boat 2: 1986 Formula 242 LS. Immaculate hull, cockpit, upholstery but the motor ( original 260 HP/ Alpha that shows 700 hrs on the meter) run good but wanted a little more reliability (ie: EFI). Was going to go the LSx route if I could sell the F-18, but no serious buyers. Decided to swap engines/ drives and sell the F-18 cheaper. In the end have a 1986 242 LS with a newer engine

I had built 350s in my Chris Craft Stinger, about 300-320 h.p. each. It had the little Alpha drives. Went through them every season (about 60 hrs.) and they always needed something. I would buy a faster boat if I were you rather than going through all the expense of a new motor and a stronger Bravo 1 drive. I have no plans other than maybe prop blueprinting (labbed) for my Fountain. If I want to go faster than 70 'll buy a bigger Fountain with big block engines.

Mount a mefi 4 and you can do what ever you wish.

http://mefituning.com/

For you owners that have the VOLVO driver package we have a package to convert your MPI/VOLVO systems to the DELPHI MEFI 4B controller. This includes ECU and all the necessary wiring harnesses. Additionally, we have packages to convert your MerCruiser ECM555 controlled engine commonly found on the 525's to the proven MEFI 4A or MEFI 4B system. Don't be locked into an expensive and limited tuning source.

either spend tons of $$$$ for very little on the EFI or cam, intake, carb...

Whipple..

IF you really have the 555 ECM your options are limited. Whipple would be your best bet. But that would be at a significantly greater cost than a cam swap.

How much more do you want out of the motor? IF you just swap the cam AND do NOT have a 555 controller it can be a fairly straight forward project. The MEFI 1-4's can be tuned by many (or yourself).