Stock-height basic engine is direct bolt in replacement for aging 80'' H-D Evolution enginesSpecially machined cylinder heads allow use of stock length manifoldsIncludes S&S performance cylinder heads, S&S standard oil pump, flat top cast pistons, S&S 585 valve springs, forged rocker arms, 508 camshaftMade in the USAFor '84-'99 Evolution Big Twin or '70-'90 custom chassis with alternator-style primary.Fuel and ignition systems not included, use existing carburetor (rejetting is required).EFI compatible - calibration required (must use aftermarket module or add-on tuner).