So my 88 has the 13.5 tank and a metal skid will that fit a 20 gallon tank ? I asked the xj group on Facebook and the responses I got were I have a 20 in my cj

 

Not sure if it would fit without modification but you could always make it fit lol

 

with time money and patience you can make it happen

 

Cj ?

 

I thought all XJs came with 20 gallon tanks... how did you determine yours is 13.5?

 

Well if you had searched, you would have found the write up and such for this, your tank can hold 20 gallons. Look up go jeep

 

The 20 gallon and 13.5 gallon tanks have the exact same outside dimensions so you can't even tell them apart from the outside. Also that skidplate should work because of this. I swapped my 13.5 on my 85xj to a 20(which was actually cheaper than the small one) with no problems at all, just I had no skidplate. The difference in the volume of the tanks comes from where the inlet tube is positioned. The 13.5 tube does deeper into the tank and when the fuel covers the end it backs up and causes the gas pump to click off, pretty sure that is the only difference between the two. There have been other threads on here about this.