Marine 273 build
TR Benj,
If the 'Domed Piston' sits below-the-deck at {-.012"}.
My calculation comes up that you are 21 CC's below the Combustion Volume
of a 273 Commando with 10.5-1 Pistons, and with the Piston set at +.129"
above-the-deck.
That comes up to about about 2.3 Compression Points below a 'true' 273 Commando
10.5 - 2.3 = 8.2 {Net Compression}
And, you are using the #675 'Open-Chamber' Cylinder Heads to boot........
which have about +4 CC's larger chamber volume than the 'stock' #920 Closed
Chamber Cylinder Heads.
That's almost another {-.50} Compression Point.
??????