This is a new cam. I ordered this cam for my block, which is a roller cam block ( Vortec block). This cam, from my understanding, will not work in a vortec block. It's for older blocks. 283-400 SBC

"IMPORTANT!"  THIS CAM IS FOR PRE-87 BLOCKS!"

Cam Style:           Hydraulic roller tappet

Basic Operating RPM Range:       1,600-5,400

Intake Duration at 050 inch Lift: 218

Exhaust Duration at 050 inch Lift:             224

Duration at 050 inch Lift:              218 int./224 exh.

Advertised Intake Duration:         270

Advertised Exhaust Duration:      276

Advertised Duration:       270 int./276 exh.

Intake Valve Lift with Factory

Rocker Arm Ratio:           0.495 in.

Exhaust Valve Lift with Factory

Rocker Arm Ratio:           0.502 in.

Valve Lift with Factory Rocker Arm Ratio:              0.495 int./0.502 exh.

Lobe Separation (degrees):          110

Computer-Controlled Compatible:            No

Valve Springs Required:  Yes