To give an idea of how hard it is to get decent compression in a 383 with a piston that gives true zero deck height, a .039 gasket & a chamber volume of 84cc you'll have right at 9.5-1 C/R & you really need a small valve notch which would drop the C/R down to 9.25.... And with aluminum heads & good quench you really want to be at 10.5+ ........... To get there with 4cc valve notches in the pistons would require cutting the chamber volume to 70cc... The short stroke makes chamber volume critical... Another reason why guys build strokers..

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