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Gmpp

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Like most production Chevy small-block engines of the '70s-'80s, the GMPP 290hp engine uses standard cast, dished pistons that only offer up 8.0:1-8.25:1 compression with the standard 76cc iron heads of the era. When used with Fel Pro PN 1094 steel shim head gaskets, the smaller 64cc combustion chambers of the Vortec heads up the compression to roughly 9.15:1.

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