Left Tank 4

To match-drill the access cover plate to the rib, it is a good idea to trace the outline of the cutout over the plate to ensure you have it centered correctly.  Although the instructions do not require, I considered it a must to seal the reinforcement ring to the rib.  Seems that would be a very easy place to leak (even with the cover plated sealed over the top).

You then go ahead and make an anti-rotation bracket for the fuel pickup tube.  It really needs to be slightly larger than 1", as you don't get much rivet hole edge distance with 1" width (the holes are predrilled in the access plate).  You will also have to enlarge the hole in the bracket to 5/8.  Most I have talked to have not gotten the fitting to lay flush with the 9/16 hole.  Be sure to install the fitting and spacer prior to riveting the bracket to the rib.

Next comes time to drill the fuel cap flange to the skin. The flange is pre-bent, so it takes some time to get it in the right orientation.  Be sure to use the filler cap to help align the tank.  You want to clamp it well, as it will want to move when drilling it.  To make the tube support, I just rolled the aluminum around some scrap 1/4" tube.

Next comes time to rivet the stiffeners.  Use electrical tape to cover the rib holes to prevent proseal from contaminating that area.  You will also want to scuff up all the rivet lines in both directions to ensure proper adhesion.