how to spec a cam?

No numbers anywhere on the cam? If it's not too big, you can measure the long end, subtract the smaller base circle, and multiply by 1.5 to get the lift. A local cam grinder, Delta Cams in Tacoma, took a cam I brought in, stuck it on a small machine with a sensor on a lobe, rotated it, and it spit out a cam card with all the numbers.