Installs without removal of fuel tank or rocker boxes; due to the shorter tapered tube when compared to the Feuling HP+ pushrods. Manufactured from tapered 7/16″ 4130 chromoly 3/8″ OD tube turned down to 7/16″ with 0.134″ wall thickness leaving heavy duty 7/16-20 threads for the base and jam nut. This is the strongest adjustable pushrod set on the market. Note: These 566072 pushrods require more clearance inside the tube covers to adjust. They therefore require Feuling 963228 upper pushrod tube kit; which must be separately ordered.