Ford Small Block 351W 1969-1996
Advertised Duration: 283/283
Duration @ .050": 248/248
Valve Lift w/1.60 Rockers: .544/.544
Lobe Separation Angle: 108
Intake Centerline: 104
Valve Lash: .022/.022
3000-7000. Street/strip, powerful through entire rpm range.

Ford Small Block 351W 1969-1996
Advertised Duration: 279/279
Duration @ .050": 244/244
Valve Lift w/1.60 Rockers: .544/.544
Lobe Separation Angle: 108
Intake Centerline: 104
Valve Lash: .022/.022
2600-6400. Rough idle, super mid-range performance, needs 11.0:1 CR-up.

Ford Small Block 351W 1969-1996
Advertised Duration: 278/284
Duration @ .050": 250/256
Valve Lift w/1.60 Rockers: .501/.501
Lobe Separation Angle: 108
Intake Centerline: 104
Valve Lash: .016/.016
3200-7200. Oval track, .500" lift rule, 1/4 to 3/8 mile 4bbl, good mid-range torque, 11.0-12.5:1 CR.

Ford Small Block 351W 1969-1996
Advertised Duration: 258/264
Duration @ .050": 230/236
Valve Lift w/1.60 Rockers: .561/.574
Lobe Separation Angle: 108
Intake Centerline: 104
Valve Lash: .018/.018
2000-5600. Fair idle, good low to mid-range performance, 9.5:1+ CR, 2500+ stall.

Ford Small Block 351W 1969-1996
Advertised Duration: 275/281
Duration @ .050": 240/246
Valve Lift w/1.60 Rockers: .539/.555
Lobe Separation Angle: 112
Intake Centerline: 108
Valve Lash: .022/.022
2500-6300. Fair idle, bracket E.T. Good mid-range torque & power, 11.0:1+ CR, 3500+ stall.

Ford Small Block 351W 1969-1996
Advertised Duration: 275/281
Duration @ .050": 240/246
Valve Lift w/1.60 Rockers: .539/.555
Lobe Separation Angle: 108
Intake Centerline: 104
Valve Lash: .022/.022
2600-6200. Hot street/bracket, needs 10.0+ CR, 3200+ stall & gears.