Hydraulic Roller - Mutha' Thumpr: High performance street/strip, needs 9:1 compression, 2500+ stall, intake, gears and headers, rough idle.; 291/311 Advertised Duration, 235/249 Duration .050", .557"/.542" Lift, 107 Lobe Separation; Adjustable valve train required; Must use bronze tip fuel pump pushrod when using high pressure or high volume pump;
