AEM boost. vac reading.
 

so my motor was reading -12 vac on the aem boost. and not its reading like -6.7 or 7-.8 . can someone help me out and tell me if this is good??? motor was rebuild 3 months ago. with street port.

-Check your vacuum line to to gauge.
-Check all vacuum lines for cracks or leaks.
-mine usually reads -15 on idle if that helps

and my car idles fine. so its a leak?

could it be just the hot weather??? in socal.

Probably a leak unless you notice the engine is running much worse than before. Fresh, stock port engines should pull near 20 in/hg. The quality of the rebuild parts, break-in process, and porting will all factor in, though.

The reading won't be affected by weather this much.

A quick way to check for leaks is to spray your vacuum lines one at a time with carb cleaner and listen for idle changes... Try not to spray it on anything hot like the manifold. It's not the best way but short of replacing all the line this can help find the leak.