Unlike transplanted Chevy type lifters, TA Roller Lifters are specifically designed for the Buick engines. These solid roller lifters have the necessary shrouding to eliminate oil hemorrhage from the oil galley at full lift. TA 1413 is for use with any Stage 1, 2 or 3 roller cam combination. TA 1414 is for use with Stage 4 heads, these lifters incorporate a .200” offset for the intake valve. TA 1104 Lifter Bore Girdle is highly recommended with the use of any roller camshaft big block.