These Jims tappet screws are made of heat treated 4340 chrome moly steel. Use these tappet screws with any High Performance, race or other extreme application. Screw has oil hole through center to lube Evolution top end with 3/8" ball end (OEM 18555-36). Use with tappet nuts fmc-233399 (9/32"-32 thread). Sold in pack of 4.
