Kits feature everything needed to complete crankshaft installation including trusted Hot Rods crankshaft, main bearings and seals; plus, a complete engine gasket set that includes all gaskets and seals for an entire engine rebuild. Owners have the choice between Hot Rods Heavy-Duty O.E. replacement crankshafts or Hot Rods Heavy-Duty Stroker Crankshafts. Stroker kit crankshafts increase length of stroke as listed depending on application; in some cases cylinder head must be modified, as noted.