Hydraulic - Magnum: Street/strip applications. 10:1+ compression, 3000+ stall or 4 speed. 4.10 or lower gears and aftermarket intake. Very rough idle. OR Oval Track: Good for hobby stock in 454 where Hydraulic lifters must be used.; 292/292 Advertised Duration, 244/244 Duration .050", .550"/.550" Lift, 110 Lobe Separation; Valve spring upgrade required
