540s with 502 mpi intakes
 

I know cam plays a big part in this, but I'm unsure of what is in motors (trying to get info from builder)
How much power an I leaving on the table with the mpi intakes and gill exhaust?
Thinking of going to 800-1050 carbs and KE exhaust

A ton and good thinking !

Dont want to hijack , but a cam that is on the edge of reversion on a 502, become a little safer with an extra 40 cubes?
Otherwise ill throw in with a mild cam reflash tb mods vs carb headers x2 may be 60ish

Joe is there enough room to get the KE exhaust to work on your set up ?

intake is worthless without stupid amounts of work, much better off with aftermarket and WAY cheaper using a good tunable carb

Is this in the Excalibur? I'd hate to give up efi for 1 mph in that boat

THe factory merc mpi intake starts running out of steam over say 500 hp, sure you can make more with it but for what it takes there are better options.

You have to do a ton of work to the intake to get it to flow anything worthwhile. I did the AS&M Extrude honed intake (they royally screwed me on that one BTW) and after making that POS right, Iron Eagle 308 heads, 540 ci with 9.25:1 CR, Bob M. .610 lift cam, and Precision Marine (Mark Boos) tune, was right around 600-620 hp based on fuel used. It was a great running motor and had a very strong low end torque albeit it ended up spinning bearings after oil pump failure. I started rebuilding and ended up with AFR heads so I ditched the MPI setup to see the gains from the heads. It is a lot of work to get an MPI to make good numbers, but I wouldn't do it again from scratch.

I still have the cam, intake, plenum, MEFI1 with matched tune and harness, and ported throttle body gathering dust on the shelf if you are interested. It would be a good head start if this is really the route you want to go. PM me if you want more details on it.

You dont have to go hog wild shorten the runners a bit fix the throttle body and get some real injectors and fuel system. But damn they sure are ugly compared to a finished cutler ,asm even the vp 502 set up with some fresh paint. Thats some real money though, just for bling factor. With the right cams and aformentioned quickys they will support 540's but they wont look like 540s .you wont get your money back from the tb fluff and plenum mill if you still want more but you wont get hurt bad either.

John, not sure if they will fit yet will need to take some careful measurements, maybe buy one and physically check. Prepared to rework exhaust to bypass those box mufflers and dump directly into side outlets if required
Goal here is to free up some power, boat is very happy at 40 mph up on top of waves, great ride and reasonable fuel burn. But I need to spin motors at 3900-4100 to get there. Hoping by helping them breath a little easier I could get rpm down.(same power lower rpm) this is not a quest for top speed increase, just more relaxed cruise.