My local machinist bored out my gen v 502 which was .030 over to ,060 inst long rods 6.385 and installed 17cc, .180 height domed pistons and balanced the rotat assy. I told him I mainly use the boat to take out people who do not like full throttle but mainly cruise but wanted a bump up from stock. I will be inst. 118 cc heads cast iron from Ron Sporl, he has been a lot of help. We both feel that that comp ratio is too high, just wanted some more opinions so when I go to my builder and tell him he screwed up I want more backing other than me and some guy he doesn't know. Am I doomed w/ the domes even on 93 octane?

Your machinist didn't do you any favors. I would go with flat tops

Yeah ... that'll likely be a bit on the sporty side for 87 octane dock gas; do you know what the deck height ended up at? You can bring the CR down a bit with a thicker gasket but you are compromising quench when you do i.e. not the correct way to lower the CR. To say you are doomed even on 93 is a bit of a stretch though; as an example 4.52 bore, 4.0 stroke, .010 in the hole, 17 cc dome, 118 cc chamber and a .027 gasket will put you at 10.5:1 so, depending on the cam you are probably on the edge. You really need to know the compression height of the pistons and whether or not the block was decked to calculate the deck height or just measure as installed.

As AllDodge says ... flat tops in this scenario is a more conservative choice if that is in the cards especially given your objectives -- Good Luck!

As AllDodge said, your machinist did you no favors. That's way too much for iron, period, and borderline too much for aluminum at true 93. Once it gets to peak torque, it's going to start eating piston crowns and ring lands.

Listen to Ron.

Are you stuck on the 118 cc heads? Alot of BB heads have as much as 123cc chambers stock. Assuming a deck height of .010 (could be much more) that would get you down to around 9.8-1 with the standard .041 head gasket. I personally like compression and wouldn't be scared of it at all. If it were me, I would ditch the steel Sporl heads, buy a set of alum ones and bolt them on and go boating on 91 or 93 octane.

I'd limit boost to 23.8psi with that compression

I ran 9.7:1 with 89 and iron Merlin heads for a few years with no issues. I just dyno'd my 9:1 mini domed 454 on 87 up to 584HP on aluminum heads at 170°F water. Have them chamber ported to 123cc, 0.041 head gasket, 130° water and send it. Or get aluminum heads as others stated.
My builder runs 10.5:1 aluminum heads on premium for the last 20yrs.

She is normally aspirated. Have not been able to contact machinist, went there today he was out to lunch and did not pick up phone rest of day. Went to builder where eng is and deck height is .008. If he won't work w/ me on new pistons and balance it may be cheaper to mill out the head as Rookie said. I know SB is kidding