Building a 273
I believe the factory Commando 273 pistons provide a higher compression than the currently available Egge piston replacement. Either a shorter dome or a varied piston pin height would be the reason. I ran the TRW forged Commando piston replacements (I used .060 overbore which works out to 282 cubic inches) back in the '70's which advertised the same factory 10.5:1 compression rating. Base on E.T. and MPH on the quarter mile (12.72 @ 108 and 3150# with driver) the horsepower works out to be about 305. Edit: 4.56 rear end
I believe the factory Commando 273 pistons provide a higher compression than the currently available Egge piston replacement. Either a shorter dome or a varied piston pin height would be the reason. I ran the TRW forged Commando piston replacements (I used .060 overbore which works out to 282 cubic inches) back in the '70's which advertised the same factory 10.5:1 compression rating. Base on E.T. and MPH on the quarter mile (12.72 @ 108 and 3150# with driver) the horsepower works out to be about 305. Edit: 4.56 rear end