okay so on my last run of the season (not by choice) it appears my block cracked right near the motor mount.
Is this a common problem?
How does this even happen?
Is this something my insurance company would cover?
would Merc. do anything in regards to this?
Oh its a 375 hp 496....
Thanks in advance for any help

The early blocks 2000-2002 were weak there we broke them racing and GM changed the casting. I have seen one welded and it held up good.
Steve

didn't think about having it welded, it appears pretty bad as the coolant pours out of the motor as soon as you put in it and as fast. and it appears there's water in the oil as well.

A mechanical failure is not going to be covered by insurance.

Merc will not do anything unless you have an extended warranty.

All 496's are thinner wall castings in the area of the motor mounts versus some of the later 502 blocks, but even Mercury racing equips the HP engines with solid front motor mounts versus the rubber lord mount type mounts the stock 496 and 502 Mercruisers get. We have broken 496's there at the motor mount racing and a few users have broken them there in rough water. Suggestion, contact Gil Marine, they make a special front motor mount for the 496 @ about $175 and its a perfect solution if you run your boat hard in the big stuff. It will require some angle mounts to the stringers but it is way cheaper and easier than replacing the block!

Best Regards,
Ray @ Raylar

Thanks Ray, will call you on Monday!

I have had my 440 mopar block "Stitched" by a guy in MA. He also stitched my buddies 383 stroker block. Its amazing to see what this guy does. Both blocks where cracked and leaked coolant. He does it all by hand,actually cuts and drills the crack and puts theses metal cast X stitch's in the crack. He pressure tests them to an extreme psi. my buddy never had a problem whith a couple of years drag racing the car. My block was just an extra and never used it. There might be someone closer to you that does this.... def cheaper than a new block but thats a tough call to make for a boat.