ProMax Direct Lube Chrysler 383-440 Mechanical Roller Lifters The lifters Pro Racers use. “Full Time” high pressure oiling (most other oiling type lifters are timed based) to the roller bearing shafts. This continuous oiling offers higher rpm and high spring pressure capability. The Pro Max features lightened, steel alloy bodies with a special enhanced finish. Heat treated stainless steel link bars. Case hardened 8620 rollers fitted with the best alloy bearings and pins. These are the same materials and designs used on most Top Fuel lifters. .300” taller body allows lifter to fit early, late model and after market blocks. Fully rebuildable. Made in the USA!