It makes sense, hotter pistons/rings and colder cylinder walls than an automotive engine but Merc does not adjust clearances in their stock motors.

Old thread, but here is an even older one on GM Crate 572s in a go-fast boat:
https://www.offshoreonly.com/forums/...gladiator.html

I personally thought it was one of the coolest things ever.
I also had a jet boat with a ZZ502 in it.

https://www.offshoreonly.com/forums/...ator-small.jpg

Basically as Kreed mentioned however I read an article how they are basically assembly lined assembled engine without the care and precautions of marine engine. Basically like an early 454/330 truck engine with much more power that could potentially lead to more concerns. On the flip side sounds like some have had great luck. No need to list what's already mentioned earlier. I'd question running a near full throttle run for 30 minutes or so. But at the same time I ran across Lake Michigan to Wisconsin full throttle twin engine 78 boat 454/330's 4,700 rpm. Was about 68 miles. Not sure if merc did anything in that era to boat engines or not. No oil coolers and oil filter on the block.

If the engine has the clearance, your good!.... If it doesnt,,,. your fu*ked....but with an expensive build, why not check.