This hydraulic roller tappet is used on the 350 ZZ3 & ZZ4 engines.
The duration at lash point in degrees (intake/exhaust) is 275/280
Duration at .050" tappet lift (intake/exhaust) is 208/221
Maximum lift with 1.5:1 rocker ratio (intake/exhaust) is 474/510.
Valve lash is zero/zero and lobe centerline is 112 degrees.
Lifters not included.
Use with Timing chain kit- 12371043
Pushrod Kit- 12371041
Lifter Kit- 12371042
Valve Spring Kit- 12495494