fuel tank filling capacities

ok so i got an 88 b2200 bought for daily driving its an extended cab truck 5 speed manual put a weber carb on it due to old one was messing up i have noticed even before the carb was replacing that when filling up with gas only holds like 7 gallons, even with it about to the point of shutting off due to about empty and refilling only will take about 7 gallons getting about 140 miles out of a tank of gas the manual says it has a 12 gallon tank on it. made sure i was filling up all the way anybody else ran into this problem??

I can put 12 gallons into my 1988 B2200 Cab Plus if I run it low enough on fuel.

Mine is the same way. If I fill up when gas gauge is on E, it will only take 7 or 8 gallons.

hummm yea i just dont get it i bought the truck hoping get descent fuel mileage especially since the weber is susposte to help fuel mileage and i keep my foot out of it too but only 140miles out a tank is kinda crappy at like 18mpg so just dont know lol

Well the quote chiltons and from recall for a cabplus it suppose to hold 14.6.Idk that I have ever put near or close to that amount over the last 25yrs with my cabplus.And yeah have run out of gas 1 time literally pulling into to fill it up cutting close was just that the engine shut off going into gas stop.

used to (no longer have the truck) get almost 400 miles out of a tank on my 90 b2200 cab plus all stock motor, if i remember right it held close to 12 gallons

You guys that can only put 7 or 8 gallons in, need to fill a gas can and keep it in the bed of the truck, until you run completely out of gas.
Upon fill up you can verify the capacity of your tank.
My bet is that your gauges are inaccurate... I know, that's an absurd assumption!

another guy that bought his truck new?? Thought i was the only one.I can never get more than 12 gallons in my 4wd I thought it had a 16 gal tank.What gives

Well I found out the reason for only getting 7-8 gallons on fill ups. It seems the previous owner cut the tank almost in half. I installed a new tank from autozone today and it is a 17 gal. tank. BTW mine is a 89 extra cab, 5 speed

Yes bought my 87 cabplus brand new.I will uncover it and check my actual owners manual and see what it says on so called gallons it holds.I rarely drive it now,but even when I did short drives and never got below half a tank kicking around town.