Can I- And how hard is it to change a GM 572 crate eng for marine app.?
I have one sitting here in the crate..........
__________________
http://www.rockyou.com/photos/photo...anceid=14044350

ddg814,
I'll send this answer, and likely someone with more info will pipe in.
It is my understanding that the following should be performed.
1) Heads - You will need to change valves and likely valve springs.
Marine applications employ a higher nickel content exhaust valve to survive the heat, and moisture of a marine application.
Severe duty intake ss valves are required.
2) Cam - If you are running dry exhaust, you may get away with without changing the cam, for a marine application it is best to obtain a cam suited for Marine loads, and generally an LSA ( lobe separation angel that does not exceed 112, 110 is better for fighting reversion. ( Sucking back water from the exhaust cooling if using a wet exhaust)
3) Frost plugs - Marine engines use brass rather than steel, which generally are supplied on crate engines.
So that is about it, Cam, Valves, Springs, and frost plugs.
I am sure that now this answer is posted, someone will pipe in to elucidate this more completely. If you perform a search, in this section, you find a great deal of information already posted.

This is incorrect. You want a bigger lobe seperation on marine engines. The wider the angle, the lesser the chance of reversion. The angle will depend on what exhaust you will be running.

The engine will work fine I am going on 309 hours

You need to make sure that use a marine carb and ignition. You may need to change the cam to one that is more suited for marine use.

change the freeze plugs too...has steel init now...put in bras or bronze or stainless.

I am running marine msd and the engine came with brass freeze plugs and the 632/632 254/264 @.050 cam works just fine with 650 fp of torque. Like I said going I have 309 trouble free hours on the engine. And if it blows all apart tommorow I will buy another and stick it back in their.

I feel for the money you can not beat this engine 12,500 and no dry exhaust needed

ZZ572 are built around an all-new generation VI one piece main seal tall deck 572 cid with approximately 9.6:1 compression, 620 hp at 5,500 rpm, and 650 ft./lbs. of torque at 4,500 rpm with a recommended max rpm of 6,000. These all-new race blocks have a 4.560 in. bore and are filled with forged 4340 steel cranks with 4.375 in. stroke, shot peened forged 4340 H-beam rods, and forged aluminum pistons with full floating wrist pins. Redesigned rectangular port aluminum cylinder heads with 118cc combustion chambers, Stainless steel valves at, 2.25 in. intake side and 1.88 in. exhaust side. Hydraulic roller camshafts are used with valve lift being .632 in. intake, and .632 in. exhaust side, duration at .050 in. for intake is 254 degrees and 264 degrees exhaust side. Hardened chromemoly retainers are used with dual valve springs 1.50 in. coil diameter, 1.800 in. installed height with 197 lbs seat pressure. Aluminum roller rockers with 1.7:1 ratios, high performance one-piece push rods are installed. New GM Performance Parts tall deck single plane intake manifold and 850 cfm Demon carburetors deliver the air. A GM distributor handles ignition, spark plugs and wire are included. New screened and louvered windage trays, High-rpm torsional dampers are used. Pump gas friendly, massive torque and horsepower, all from GM Performance Parts.

Ditto...
Simple Math.

There's your answer.

This old thread may give you a little more insight.
http://www.offshoreonly.com/forums/g...ing-today.html