This listing is for a set of (8) stainless steel exhaust valves and (8) intake valves compatible replacements for SB Chevy engines. The exhaust have 1.600" head diameter, 4.905" stock length, and .3415" (11/32") stock diameter stems. The intake have 2.020" head diameter, 4.905" stock length, and .3415" (11/32") stock diameter stems. Both have undercut stems and a .250" Tip length. These are One piece valve forged from high quality 21-4N stainless steel with hardened tip Chrome plated and undercut stem with swirl polished head for improved flow. No oil seal groove in stem to weaken them like other valves. Kit includes valves springs for up to .480" lift cams, locks and retainers. Recommended maximum spring pressure: Installed 140 lbs. - Open 400 lbs. They will fit many small block Chevy 283, 302, 305, 307, 327, 350, 383, and 400 V8 engines and also could fit many aftermarket heads from Dart, Edelbrock, Pro Topline, and World Products depending on the head diameter size and length you need for your application.