Is it just me or what. For a 496HO (425hp) Mercruiser wants roughly 14g's ready to drop in without exhaust. For $7500 i can get a zz502 (502hp), there are a few changes that others suggest(distributor,cam,valves,marinize the carb) but i see some running it with the original zz cam,lifters, and valves. Even if i swap them out i am way under 14g's. Am i missing something from the list to convert the ZZ502 over for my boat that i have not listed.

brass freez plugs.

I have an old 7.4l that i am running the zz502 cam,heads and intake on and have had no reversion issues. I am thinking about changing the cam to get that little extra hp

Buy U, I can get you a matching cam for the motors I just built for $100. $75 for the lifters. New in the box. You'll like it much better.

probably just the black "gold" paint

Just the warranty if it pukes.

Yes that is the truth.

I know a guy that is having awesome reliablity with the GM Towing crate engines. They are around $5800 a piece. make 500 lbs of torque below 4000. They came with everything except exhaust and sea water pumps. He dropped them in and never looked back 4 years ago. He rarely even changes the oil. Go figure.

I was told that the brass freeze plugs were for salt water use only and not needed for fresh water. Looks like a ZZ502 is in the near future.

everyone "knows a guy" who put a car engine in and it worked......

and everyone knows a few guys who it did not work for....

the merc stuff works, time and time again, over and over, right out of the box.

One mis-step with the zz-502 and you lose a motor, then you are spending more than the 496 ho cost. Plus you lost all boating season screwing with it, and to get it right will now cost $20K instead of $14K.

I been down the road you are going on, and strongly advise against it.

What kind of engine are you running now?

Comparing the price of a Merc 496HO fully marine equipped to a crate 502 is not even a close comparison.
Take the 502 and change the camshaft, add coplete electronice EFI fuel system, add closed cooling, oil and powersteering coolers, marine motor mounts, bravo bellhousing, bravo coupler, raw water pump system, complete engine harness, coil near plug iginition system, ECM , etc, etc, etc, and you will be well above $14K. You are comparing apples and oranges! The only thing you really get when you try to get a fully equipped reliable marine high performance engine for "almost nothing" is Nothing!
Good Luck!

Regards,
Ray @ Raylar