Hydraulic Roller - 4-Pattern .900" Base Circle: Best choice for street 383 stroker engines with good cylinder heads. Very wide power range. 2600+ stall.; Outboard Specs: 289/301 Advertised Duration, 236/246 Duration .050", .630"/.618" Lift, 109.5 Lobe Separation; Inboard Specs: 287/299 Advertised Duration, 234/244 Duration .050", .627"/.614" Lift, 108.5 Lobe Separation; 2400 to 6700 RPM range; Recommended use with 1.6 rocker arm ratio
