sr_ryan1

i have a 4 bolt main 5.7 casting number 3970010 engine and need a Compression Ratio of 9.4:1 to work with a mercruiser 350 mag MPI system.
this is going on a boat not a truck so i need to know what heads, piston, and cam to build this.

can anyone please help me?

sr_ryan1

man the hell with that mpi system. im just gone go carbed

so what is a good head and cam pakage that makes power thoughout 1000-5000 rpm range?

mrdragster1970

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Call Brodix.

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sr_ryan1

the outdrive can only take 300 hp

mrdragster1970

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In that case, stock rebuild. Good luck.

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92builtbird

yeah, if it can only take up to 300 hp, my concern would not be bumping up the compression. compression= power. stick to about 9.1 or lesser.

78LT383

do you have any heads now?

ATCFLYBOY02

iTrader: (7)

A stock mercurser is rated at NO MORE than 260hp. Seriously, I've been playing with boats just about my ENTIRE life.. If you have an ALPHA foot, go with a stock build. I've replaced over 10 of them on a Baja that I have at homebefore I upgraded to an Alpha 1, with a 260 hp Mercurser and a cam. Go with a stock build, being that you will most likely be turning 3-5K, I'd go with at least a steel crank (some came stock w/ one, make sure you check)