Seem to remember that there is something different from marine engines to passenger car engines? Is this True???
If so what are the pros and cons?

reverse rotation engines I think...different cam obviously.

As faras I know, the blocks are the exact same, but be careful of marine engines, especially if they've been on ocean water, lots of rust due to the never ending supply of straight water or straight salt water for engine cooling. a marine engine has never had anti-freeze corrosion protection inside of it.

Partly true..not all marine engines run backwards.In a twin engine boat only one runs reverse rotation..Most Chrysler marine engines were fresh water cooled..therefore were filled with antifreeze..the blocks were the same and almost all had steel cranks.I have one sitting in my garage in NJ for two years...came with low comp pistons.steel crank and very little use..could be used as standard bore 440..I am a retired marine tech and marina owner..PM me if you know anyone who wants it..

They are the same if the rotation is the same.
Depends in the drive unit.
I had a Silverton, with twin 440's
sealed coolant system and ran antifreeze in both.
Both engines were standard rotation.
The V-drives were different.
One is a 2 gear drive, the other is a 3 gear drive.
The 3rd. gear is what gives you the reverse rotation to the prop and shaft.

The reason for reverse rotation in twin engine installations is to offset massive torque steer from both props spinning in the same direction.

On the reverse rotation motors, the crank's rear main seal knurled surface is cut in the opposite direction.

Years ago I had an old 413 marine; had to punch it +.060 to clean up. Cracked a cylinder wall first trip out after the rebuild due to it having an open cooling system & it had been run in an old fishing boat in salt water for a couple of decades.