I have three different pairs of defroster ducts I've purchased over the years, and one that was actually installed in a cab, that were intended for my 39 GMC pickup. All of these have been ebay purchases, and all of them were advertised as being correct for a 39. In the following link you'll see all four types. I have them labeled A, B, C, and D, in order of acquisition. A was an ebay purchase. Duct is too wide and does not fit the opening in the 39 dash mount. B was the next ebay purchase. I think this may be a universal fit type. It fits but it's actually a bit narrow, and does not seat into the dash. C fits perfectly, but does not have a flange with provision for the typical spring clip that is used to slide on to one side and fasten with a screw on the other side. D is the one that was actually installed in a 39 cab when I got it. It does fit perfectly, but is unlike any other vent I have seen. It's pot metal, and as you can see much smaller, and has very oval hose connection end, where all the others are round.
Can anyone help me ID these various ducts? Are any of them technically correct for a 39 Chevy or GMC pickup? Strangely, this 39 Chevy cab, which is a US Forest service truck ( has the logo etc. on the doors) has a deluxe GMC heater in it that looks like it was born there.
Thanks!
Defroster Ducts
