1989 200 QT Appears to have no boost. The gauge reading is telling me I am running vacuum. Where should I start? I am new to this car but very mechanically inclined.

 

Open to further discussion, in order for your compound gauge Boost/Vaccum to be correct a Vacuum would require the Turbo to be able to spool in reverse. Vacuum reading on a Turbo charged engine where the probe is inserted into a line under boost pressure between your turbo clean air (boosted) discharge - and your Engine"s Primary Air Intake assembly, should never be able to draw a Vacuum.

 

so is 0.3 just a low boost reading then?

 

Sounds Correct... Non existent boost or minimal at best....