Thanks gentlemen. I probably should have mentioned that I have a rear gas tank which prevents putting the spare tire underneath. Hence considering the inside spare for several reasons: 1) It's mostly unused space, 2) it's protected from theft and the elements 3) it's accessible for maintenance (ever have a flat tire and discover that your long-neglected underneath spare has 5 lbs of air?). The weight on the passenger side also will help compensate for the absence of the fuel tank on the right side. And as my signature line states, it's a panel truck so no need to worry about passenger access.
