I decided to use an '88 GMC k2500 for my 4x4 conversion. The gas tank was outside the frame before '88, so that was one thing to consider. '88 and later had the primary gas tank on the driver side and the secondary in the rear, I moved the filler to the driver side, but I think it would have been easy enough to move the tank to the passenger side. I was able to get the ride height the same as original and the tires are not outside of the fenders so I'm happy about that. I'm not sure how the width compares between '38 and '47.2 though.
