OK guys and engine shops need help here Looking for good 496 or larger engine, must dyno and spec out ok before purchase or new or nearly new block, or short block ,or rotating assembly dart pro1 heads preferd. Have used 420 hp merc to partial trade. Several options may work I have ignition, carb and intake, also have extra 420 hp crank, rods, pistons, cam, 990 heads, intakes, ignition. thanks Dan