What is the difference between a Vac and Boost gauge? I know Boost has "negetive boost" which is technically vacuum.
Would either work to measure vacuum, or should I stick with a real vacuum gauge.
Well if you plan to stay NA I would get just a vacuum gauge. If your planning to go boost then get a bost gauge, and it will only read on the vacuum side.
FU Tuning
if ur not going to boost stick with jsut vacuum, negative boost is vacuum but a vacuum only gauge is ore accurate at ready vacuum rather than presure

I may run 18s, but I can do your taxes in 10 seconds flat.