Chain drive. This Feuling M8 camshaft kit includes chain drive camshaft; Race Series lifters and a cam installation kit that includes cam bearing; cam/crank hardware and a gasket/O-ring kit that allows for install of the factory one-piece pushrods. Feuling recommends the optional 993528 Feuling one-piece heavy duty HP+ pushrod kit; with 0.165" wall thickness. Feuling rocker box fastener kit 707450 is also highly recommend to help prevent cylinder head cracking; this kit replaces the rocker shaft bolts with studs and nuts to help reduce the stress on the rocker shaft standoffs.HP+ kits come with HP+ lifters and RACE SERIES kits come with RACE SERIES lifters508 CAM - ''The Grim Reaper'' Aggressive pulling power with a "nasty" sound. This camshaft revs up faster than the 521 grind; sounds nastier and pulls harder but is more difficult to tune. The REAPER 508 grind will shine in 114" and larger cubic inch engines with added compression ratio. Ported cylinder heads are not required but will complement the cam and add even more pulling power throughout the range. The stock throttle body produces an excellent powerband and use of a high flow throttle body will increase peak power numbers. A high flow exhaust system and air cleaner is highly recommended for optimal performance. FEULING recommends matching this cam with the RACE SERIES oiling system 707407.NOTE: High Lift valve springs are required on stock cylinder heads; see FEULING BEEHIVE valve spring kit 993530 or 588021.