Plugged the valve timing events into my calulator for the zz4 cam here's what it spit out:

Inputs:
Intake Valve Diameter: 1.94"
Exhaust Valve Diameter: 1.50"
Intake Opens: 23.0
Intake Closes: 72.0
Intake Lift: .474"
Exhaust Opens: 73.0
Exhaust Closes: 27.0
Exhaust Lift: .510"
Rocker Arm Ratio: 1.5:1

Outputs:
Intake valve lift: .071 inches
Exhaust valve lift: .077 inches
Degrees Crankshaft Rotation:
Intake Duration: 275.0
Exhaust Duration: 280.0
Intake Center: 114.5 ATDC
Exhaust Center: 113.0 BTDC
Lobe Center Angle: 227.5
Lobe Center Point: 1.5 ATDC
Overlap: 50.0
Degrees Camshaft Rotation:
Intake Duration: 138.0
Exhaust Duration: 140.0
Intake Center: 57.3
Exhaust Center: 56.5
Lobe Center Angle: 113.8
Lobe Center Point: .080
Overlap: 25

You guys think this is accurate??? Duration is different than the 208/221 @.050 that GM advertises. Just tryin to help out some thirdgener's as I coudn't find LCA and Intake Centerline for this cam anywhere.

 

Go to the motion software site and download the trial DD2003 it has a cam manager that tells you what you want to know.

 

The intake open/close points don't seem to make sense. Are those measured values? If I'm interpreting your data correctly, the intake opens at -23° and closes at -72°, or 311° of crank rotation. Or did I misinterpret you results? If the intake closes at +72° you're only measuring 95° of crank rotation for the intake cycle, which is way too short. The intake opening point seems about right, but it seems that it's clopsing very late. If the number are actually -23° and -72°, it appears that the valve timing is really retarded (late).