Gas Tank Size for 91 D150

[TommyDodge]

I filled up the gas tank today on the 91 D150 and it took a little over 22 gallons, and was wondering what the capacity for the tank when full is
My 88 D100 had a 21 gallon tank and I thought that the tank on this truck was the same, but apparently not
Thanks!
DB69

[DODGEBOYS]

when empty [ on the gas gauge ] most tanks have a 2 to 3 Gal reserve / so you musta ran it real dry