They hosed me on the stainless steel braided lines !!!!!!

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I'am working on a project the starts with the 6.2 MPI. I would bet the same pistons are being used in the Scorpion, sounds like the forged pistons are not holding up. It has a 4340 crank, but most likely the 5.700 forged rods as found in the 5.7. They are called forged; that not being a 2618. I will let you know how it goes on this project.
Figure in boring to 4.030, CP pistons, AFR 190s, cam, lifters, rocker arms, push rods, rebalance and the Holley Stealth HP EFI. Throw some tubular headers on top of that. $$$$$. This isn't a budget build. Figure the cost; of EFI, then figure in a intake, carburetor, flames arrestor, fuel pump, distributor, wiring harness, ignition box, you will be over 1k in those parts alone. You can throw some iron eagle heads on there, they will make power. I saw a video; taking a set of 882 and working well over in the tune of $1000+, run them on a 383 carb, take them of and bolt on a set of Iron Eagles, the Darts blew the 882s away. If I can find it I will post it up.

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Very interested in these builds Bob. Looking forward to the results. Will these N/A builds be okay on 89 octane?

Wes, I've not tested the small block CMIs. I have done several sets on 496's with before and after dyno tests. I saw 28 HP increase with the sport tubes at the prop on a 496 HO. I certainly would not expect more than that on a small block, probably less.

CaptainYARR's engines will run on 87, the other 2 are higher compression and will require 91.

Are there still problems with pistons on 6.2 MPI's or did Mercury Mercruiser introduce an improved piston design at some point to fix the issue ?

I blew one piston on one and a head gasket on the other with about 200 hours. Year 2004 motors in a 2005 boat. Bobl suspects ethanol clogging injectors. No matter what the cause, it looks like I'm in good company.

I have no idea, if there was a correction to that. I doubt; they would change the piston, if it was caused from injectors. I spoke to Bob,( Marine Kinetics ) about the issues with the 6.2 and the 383 Scorpion. He mentioned "inverse radius",on the lobe ramp, was the issue with the valve train. I know he will be happy to give the technical break down. This isn't the first time we have discussed "inverse radius".
My client has pulled the trigger on building the 383 off the 6.2 . We had a discussion about just selling the stock 6.2 complete, minus the front accessory pulley brackets, sea water pump, alternator, and power steering. I'am putting it out there starting at $5k and would accept a realistic offer, if we can cover, building a new short block. The boat is well taken care of, the engine has 300 hrs. He also has a Y pipe, silent choice, and tips, if someone is interested.

Forgot to tell you. The injectors were so clogged up they didn't even try to run a "before" flow test, according to the injector service. They all cleaned to flow within spec though.