I installed my boost gauge and when I start the car the needle stays on 20 and when I hit the gas raises up to 10 like the gauge has 0 -30 reading going up or going down I'll try to get a pic

 

These readings all sound normal. The gauge reads from 30 inches of mercury to whatever amount of boost. Most gauges look like this:



So a reading of 20 inches of mercury at idle is perfectly normal.

 

Yeh it looks like that it starts on 20 in the negative then when I get wot it hits 10 in the positive I have the s /c with 9.5 pulley so this sounds correct?

 

Vac @ 20 is good at idle. Until you put some kind of load on the motor you won't go into boost if you're just reving it.

 

With that pulley, sure does sound right.

 

^^^ what they said.

I'm NA but my "Boost" gauge (Vacuum gauge) reads -20 at idle and goes up to 0 at WOT. 9.5lbs boost = 10 reading on your gauge is correct, it's supposed to show how much psi you're using in boost.