how many gallons is the 2600i tank

just wondering how many gallons is the 93 b2600i x-cab tank?
my gauge doesnt read correct and i just keep putting more gas when it gets to 1/4 tank.

does anyone know how many exact gallons it holds?

in my 91 b2600i there is 14.8 us gal.

i found it in the owners manual.

Peace N|ck