All I have is a hand pump with a gauge on it. If I hook that up to one of the vacuum nipples at idle, will it read the manifold vacuum?

 

yes, but the increments on a vacuum pump guage are larger so it will make tuning dificult due to very minor diferences shown on gauge.

 

Not for tuning, I just want to see how much vacuum my engine is pulling at idle. Do you know what's a normal reading for a 13B with mild street port?

 

I connected the gauge to the nipple where vacuum switch connects, and it read about 17in. Is that good or bad? Oh and when I disconnected the vacuum lines from that nipple, it was hissing and sucking in air, but it didn't actually seem to affect my idle at all. Why is that?