If you can, place the cam in the engine. Take a solid lifter and install a dial indicator so it is touching the top of the lifter and zero the scale. Wit a degree wheel and pointer turn the cam slowly until you reach .050 lift. Record the number on the degree wheel. Continue turning until the dial indicator reaches the highest reading and record this number. Now tiurn the cam until the dial indicator comes down to .050 lift and record the reading on the degree wheel.

The degree wheel total between the two numbers will give you the duration at .050. Multiply the maximum lift number (off the dial indicator) by your rocker arm ratio to get maximum lift.

Do this for both the intake and the exhaust lobes.

To get lobe seperation angle will be a little more difficult, but basically, measure degrees of rotation between intake max valve lift and exhaust max valve lift.

Good luck.