So if the vent tube length is the only difference, why did you have to upgrade the fuel pump?
That was the reason for dropping the tank in the first place, it was time for a new pump. The only difference between the pumps is the fuel gauge, there is no reason to replace the pump with the extra 4 gallons.
If you enter your Jeep's VIN on this site you can determine what size fuel tank you actually have.
https://jeep.custhelp.com/app/jeep/eqlisting_detail/session/L3Nuby8xL3RpbWUvMTQxNzg5NDMzOC9zaWQvUzV6Qm9lOW0=