so i got a 88 mustang lx with a 5.0 h.o. my gas gauge reads all the way sometimes and sometimes it looks like its displaying. but im not sure how accurate it is considering how it goes all the way up sometimes. any hints on how i can fix this? i need to know my gas level accurately!
thanks for the help

 

I had that issue with my first car, a 95 Taurus. It turned out to be the sensor in the tank. Got that replaced and it was just fine.