Jims Replacement Tappets For Harley Big Twin Features: These tappets will run in cast iron or aluminum tappet blocks Recommend fitting the tappets to the blocks with a clearance of .0007 to .0012 Produced from billet bearing steel A true center-line for roller life and exact cam timing State of the art pushrod seat, machined with the same segmented parabolic cup as the Jims roller rockers Sold each Made in the USA