With tank in wing, I measured fuel cap opening, marked center and screwed in template for drilling 3" hole for cap. Marked location of fuel tank quantity fittings with template. Measured for rear pickup fitting. Drilled all holes and deburred. Vacuumed tank out. Installed fuel tank pickup and fuel quantity fittings. Used blue loctite on nuts. Measured and marked top of tank for fuel cap flange. Drilled screw holes and deburred. (On this tank, I drilled the 3/8" hole for the vent at this point. On the left tank, I drilled out this hole for the vent after attaching and prosealing the cap and pressure testing the tank. Doing it this way, the way the plans suggest, I found it difficult to drill the tank and not damage the threads in the inner flange. I had to tap those threads as the bit damaged the first few threads. This time, I drilled the 3/8" hole in the tank first and installed the vent along with the other screws. I will seal this vent hole when I pressure test the tank.) Vacuumed tank again. Installed fuel tank support and inner cap flange with temp bolt. I prosealed underside of cap flange and installed with screws and the vent. Will let setup overnight. (Just a note: I used disposable 10cc syringes to mix and apply the proseal. Seemed to work well and was not too messy).