HUNTER'S 1978 GMC C15 SIERRA BUILD THREAD
Here's something I found a little interesting, both of these filler necks are from 1978 trucks. The difference is one is East Coast and the other is from the West Coast. My truck has a little flapper in the filler neck and the one from the West Coast does not.
Filler necks are something that we haven't really come to a conclusion on. We're thinking about welding the ends off of later model filler necks or using 2 sizes of hose and an adapter from
this website. The reason you have to do this is that the filler necks are fatter on the later trucks and these are '87 tanks. My bedside does not have doors.