The new 502 mag is 380hp, and 502 mag "HO" is 430hp. Kind of like the old 496 and 496ho, the "ho" gets ya about 50hp

ok i forgot about the ''HO'' !!!!,, http://fastboats.com/mercruiser/2012...e-8-2-mag-ect/

pretty sure GM still casting the blocks, they still sell several different 502 "crate engines" in the performance parts section...

8.2 is smog/catalyst engine, while it looks like 502mpi, it ain't. intake, block and internals are different from previous similar looking engines. piston/ring package holds back oil to keep from clogging cats. mercury sets blocks up similar to how the 6.2 and 383's are machined/stress relieved on cnc. mercury had presentation explaining the differences when first came out.

Good info Keith. You say the internals are different, does that mean a cast rotating assembly?

Mercruiser puts together this 8.2 version themselves. What I heard is they buy the block from Dart in Michigan. Mercruiser now is Dart largest customer. The intake and heads are made by Edlebrock. with Mercruiser input.

The 5.7 / 350 CID will be going away in less than 2 years.They (Mercruiser) will be building that motor also unless they change their minds like they did in 2010 about doing a LS motor. Mercruiser did a full year testing a LS based marine motor and decided not to bring it to market back in 20010 / 2011.

saw a press release on this today, they say they are using a GM block thru a special deal they put together with GM

Catalyst converter = lots a heat ??????????

Yes, quite a bit.

The cat also have a water jacket, the excess heat (the cat itself must operate at a rather high temp) from the cat is dumped in to the sea.

Should not cause any het related issues, except the extreme wallet friction when the time comes for replacing the cat and manifold unit, $$$$$