273 rebuilt but way low compression

perfacar said

hi, ran your numbers, comp is 8.07. easist way to fix this, is surface heads to 58 cc, use the mopar thin gasket-.028, comp ratio, is 8.96. if you look at the specs on the motor, pistons are set at -.011 down, .028 , gasket, 57.3 cc head, comp os 9.70. not bad for a low comp motor.

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I don't know what formula you used??, but what we use at the shop I work at, we build engines, we came up with 7.7. And with a web site calculator I came up with the same. Also has 4 valve reliefs you need to take into account.

Those specs are meaningless.

My pistons are down .045. I measured them. The heads are 65 cc.