David, I have to buy one but when i get a compresion gauge , what should each cyclinder read?Or anyone else can chime in ! Thx for the help. 
According the Haynes manual, mimimum is 100 psi with a maximum 21 psi differance between cylinders. Take that with a grain of salt, it's from the Haynes manual. I'm thinking for stock piston/cyliders and heads, it should be about 120 when everything is new. I know for a fact that the engine will still run with less than 100 psi per cylinder, but it won't have much power (been there, done that). So, 100 psi minimum may be correct, but I would be a lot more concerned about the difference between cylinders. 21 pounds sounds way high to me. I've always been told anything more than 10% differance between lowest and highest is bad.
That's my 2 cents worth . . . which isn't worth a nickle.

I'm sure David will get us straighened out on the subject next time he strolls through here.
