M103 intake vacuum specs? Smog related
 

Is there a spec that is normal for the M103 engine?

According to this site http://www.aa1car.com/library/converter.htm
it states that normal intake vacuum should be ~16-20 inHg....I'm getting ~11-14 inHg, but I want to see if that is normal for the 103.

Gotta get my 2.6 smogged and I don't want to fail so just checking everything over. Not sure if its time to get the cat replaced or not and if exhaust backpressure could be the cause for a low intake manifold vacuum....I definitely have no vacuum leaks.

Here was my last smog....As you can see, I passed literally on the line.
http://w124-zone.com/downloads/photo.../PASS_SMOG.jpg

I think my cat is fine because my CO is very low, but I may be mistaken...this whole emission thing is part logic and part red tape voodoo magic.