New guy with a/c issues

[manfromthenasty]

Hey all, I recently came into possession of a 1978 gmc k15 with a 350 in it. It is a family truck, Granddad bought it new and I got it for graduating from college. Anyhow, the old guy got it in his head that the a/c wasn't working like he thought it should, so he opened the dash by way of the glove box, found some of the ducting to be old and full of holes, and ripped everything black and plastic out and dumped it on the garage floor. If one of you folks could post a few pics of a properly assembled under dash, it would be wonderful. My haynes manual doesn't cover this particular problem.

Not sure if imgur is welcome on this site, but this is the truck. http://imgur.com/a/Lkdvb

Thanks all.