I had a feeling cat was required, not an overpriced option...next will be yearly emission inspection stickers.

Ok, this is gonna happen again. The cat exhausts don't fit earlier engines? Adaptor plates possible? Because then it is pretty much retrofitting the sensors to an earlier intake.

what year ?

Thread title says 2011. Apparently 2011-up...

So, rereading the other thread on this engine that was just resurrected, it looks loki this guy is a custom built copy of a gen 6 502. If people can pull the cat exhausts and replace with standard aftermarket manifolds, I can't see any reason we couldn't retrofit an earlier gen engine with this exhaust and intake. The heads are gonna be either rectangle or some variant of the L29, which is doubtful. And 2011-up heads will probaby bolt to a gen 6 502 block anyway. So it might be possible buy a new or rebuilt gen 6 502 short or long block and buId an ect engine to make the powers that be happy. Needless to say, the correct cam will also be needed.
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sure one .can ^^^^^^^^

this guy can but an OEM dealer is not and Merc is not going to sell him a engine nor Volvo will not sell him anything NON CAT. He can buy what ever he wants to, .but it will and would have to be from an NON true marine place that does not deal with the marine OEM's

how things are changing for dealers and marine remaners


https://www.perfprotech.com/blog/art...nd-boat-motors

And selling it down the road and or trading it in can present issues

Down the road it will end up like if one removes the catalyst from their personal OEM autoo

So, I picked up an 03 502 461 hp GM counter engine. Big plate riveted to it saying NOT FOR MARINE USE. I assumed it had to do with the cam and head gaskets. But I guess even then they were worrying about being caught out supplying the marine market with engines that weren't emissions compliant.

So this whole thing we do with messing with our engines to make the boat's faster is gonna become illegal eventually, unless we keep an old hull around.