Well it took me a while, and the pics are super great, but here's what I've got. I can pull the fuel filler out and get some better measurements if you need. That one's gonna be a bit tricky with the curve of the bed side.
Wow...looking at them, those came out worse than I thought.
The 1" is lined up as closely as I could get it with the "edge" of the pocket.
The sun was in my eyes...my only excuse.
Tape starts on the front edge of the bed.
Tape starts as closely as I could get it to the top of the bed.
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank