88 fuel tank 13.5 or 20

long story short, i had to replace OEM class three hitch/ rusted out real bad/well with beating around the rusty old fuel tank trying to get the 20 yr old rusty bolts out.it now leaks at the weld seam where the to halfs were put togetherif i want to step up to the 20 gal replacment what all will still fit from the other?? like straps, fuel pump, skid plate, ect?? any mods i need to know about before i take the plunge into i can go 350 miles instead of 250 on a tank. thanks for any input/ Dave

if i remember correctly, the only difference in the tanks is how far down inside the fill tube goes and the sending unit. the 13.5 gal tube goes inside farther and wont allow ant more gas to get in the tank once the fuel level reaches the bottom of the tube.

what about the pick up on the pump?? the same?

thats part of the sending unit