I don't think latex will hold up to the fumes if there are any....I bet if you can find a ball pressure gauge with low psi increments that you can somehow mount or screw into a fitting, it will work...especially if its digital.

Gas tank junk, pitted holes everywhere!!!
 

Gas tank is pitted and done, new one made in Florida on the way. BOAT-
Bust out another thousand!!!!!

:clap:

Where are you getting your tank from in FL?, Just wondering.

gas tank
 

I don't know, will ask and let you know.