Here are the dyno results for a 343” Y using a set of Mummert ported aluminum heads. It’s a 343 incher by lieu of a 3.810” bore and 3.76” stroke. The compression ratio is 13.25:1 using Diamond popup pistons designed specifically for the aluminum heads. The camshaft is a symmetrical Isky grind with 263° @ 0.050”, ground on 108° lobe centers, installed at 106½° intake lobe centerline, and 0.592” lift. The rocker arms are Harland Sharp 1.6:1 roller tipped units assembled on Verne Schumann shafts. The carburetor is a Holley 780 cfm dbl pmpr which sits atop a 2” tapered carb spacer and a ported Mummert aluminum intake. Spark plugs are Autolite 3923’s gapped at 0.035” and using a MSD distributor and ignition. Click the link for the larger version of the dyno sheet.
Link to the dyno sheet
Lorena, Texas (South of Waco)