Under bed fuel tank

[1966FLEETSIDE]

Hi folks so I got my tank mounted I think I can tackle the fuel lines by my self. What I think I'm gonna need guidance with though is centering the fill tube on the wood. Once the bed is mounted. Any tips is greatly appreciated. Thx

[PGSigns]

Here is how I did mine when I installed my boyd tank. I measured from each of the frame rails to the neck to find out how far the neck was fro center. Then I used that measurement to find out what board it would under. I removed that board and put the bed back on. Centered up the bed using the mount bolts and by eye. Then took tape and put it on the boards on either side and put reference lines on it. Took measurements from the reference lines to the center of the neck. Dropped the board back in and transferred those measurements to the board to lay out the center point and used that to drill the hole with a 3 1/2" hole saw. Worked like a charm.
Jimmy

[The Rocknrod]

I've been pondering this myself. My plan is to use a short flat pencil from underneath. Then remove the board for cutting. It'll be tight but I think I can do it.
Will it be more difficult that way? You bet, but I think it will be the most accurate. Only time will tell.

[vin63]

I don't like attaching a filler neck to the bed floor...I usually do an access door. Similar to PGSigns, I made reference measurements, located the board, and made the cut out for the door. Here's a before and after.

[mongocanfly]

Or put all the wood in the bed floor except the piece where the filler is....use a sacrifice piece short board to determine where the hole needs to be...once you get it like you want ,then transfer that to your good board...