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ok...so now I have some real numbers to work with. The measurements were taken many times over until I had a fairly confident process with repeatability.

Quench clearance w/no head gasket = 0.045"
- Heads were torqued to approx. 35 lbs
- Used rosin core 60/40 solder over length of step
- Crushed 3 times at TDC
- Both ends & middle of solder measured & averaged
- All cylinder were within 0.005" of each other
- Very little piston rock was noticed across the solder

Piston step head to deck = 0.039"
- Piston brought to TDC with dial indicator
- Measurements made with straight edge & feeler gauge @center of piston

Flat of piston (valve reliefs) to deck = -0.034" below deck
- Piston brought to TDC with dial indicator
- Measurement made with straight edge & feeler gauge @center of piston

Head CC's
- All were 82-83 CC's
- One was at 80 CC
- Double checked all measurements
- Allowed water to sit in chamber for 15 minutes w/ no valve leaks observed.

Head bolt bosses at the exhaust side were also checked as suggested, and were at 0.975" indicating heads were most likely milled.

Looking at the numbers, with a 0.020" head gasket the quench area will end up at 0.065", which is far from ideal.

Also looks like compression is somewhere at 10.5:1.

Any thoughts?



Yes at .065 you basically have no quench , it is what it is unless you want to cut the heads .020 , I'd cut .025 because of your .005 variance , but then your compression is going to be higher.

Drop your head gasket on the head and see how much overhang of the chamber there is inside the gasket, scribe the gasket onto the head, drop 1\4" dowels in the head to hold the gasket, and scribe the chamber size and grind all the overhang away and polish the chambers and see how much you raised the chamber CC.