[elhigh]

A Scangauge will do everything you're asking the vacuum gauge to do, and be a lot more precise.

I have a carbureted Toyota Truck, pretty similar to yours in specifications except it's about as computerized as a 2x4. I have a vacuum gauge and frankly it's a letdown.

It's lost calibration twice (fixed it once, haven't bothered since) so it's really only good for showing whether you are pulling a little more or less vacuum moment to moment. An SG will give you much clearer information.