Fuel and vent line grommets
Van's specify (DWG 39) AN931 grommets. They require 3/4" and 1" holes.
Why not use SB-437 bushings?
Or, is it actually possible to install (push in over the skin) the grommets with the vent/fuel line inside the grommet, allowing the AN818 nuts to pass through the skin holes?
In other words, can you fabricate the line with grommets, nuts sleeves and flares on both ends and then feed nuts and line through hole in skin and then push the grommet in place in the skin?