55.2-59 57 Fleetside C4 build

[Daze57]

57fleetsidec4
As far as i can tell the hole in the vent frame is just to hold the rubber gasket in place .
if you notice on the gasket -a bump about where it fits into the frame -as you put it together -it;ll line up with the frame hole,
that;s the only thing i could come up with . also i use a dish soap and warm water to put the gasket in ---makes it easier to slide the gasket on .