As the subject mentions... We are also trying to figure out the cam specs using a dial gauge it should be pretty straightforward I think?
 
Cheers,
 
Rob

Bowl diameter on low comp (8:1) pistons is 62mm
If you have a smaller measurement they'll be high comp (9:1)

Best way to work it out is to "cc" the pistons.
You will need a burette (I use a 50cc plastic one) or a large syringe (say 10cc or 20cc).
Get the piston to TDC and add oil until it reaches the top of the piston.
I usually use auto transmission fluid as it is easier to see what is going on.
Using a syringe you will need to count the number of refills/empties.
A burette is much easier.
A standard high compression (9:1 ) should be around 42cc and a low compression piston should be around 50cc.
I then use a syringe to suck out the oil, then use tissue, toilet paper or hand towel to soak up the oil.
Then drop the piston to the bottom of the bore and wipe up the rest of the oil.