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Here is a quick recap of the motor before we tore it down. The Dart Big M block features four-bolt ductile iron main caps, has a bore range of 4.250 to 4.625, and reconfigured oil passages. The rotating assembly consisted of a forged 4340 chromoly-steel crank and I-beam rods from Eagle, JE 30cc domed 4.280 pistons (10.25:1), Big Mutha Thumpr from Comp (intake/exhaust 0.522/0.507 lift, 295/312 duration, 243/257 duration at 0.050, and a 107 lobe separation angle), Ultra Pro Magnum 1.7 ratio roller rocker arms, Weiand high-rise/dual-plane intake, Holley 750 cfm Street HP carburetor, MSD Digital E-Curve distributor, ATI's Super Damper, Moroso billet spur gear oil pump, and six quart pan. That combo, with 80 primary and 84 secondary jets, put down 507 hp at 6,000 rpm and 471 lb-ft at 4,100 rpm. Not too shabby for a 427, but we found out there was more to be had.