[Terry M. Hunt]

I posed this question in a previous post and Cardo gave me some input. I want to put this out there one more time before I give up on the issue. Attached photo shows 2 different fasteners that are supposedly used to attach the evap case to the firewall on a 66 GTO. Screw 1 is pretty obvious, but stud and nut 2 is what I’m trying to pin down. The example in the photo came from our host and is listed as. P120YJ 1964-72 AC Evaporator Housing to firewall Stud & Nut. When I ordered this part I. asked if they had any info on exactly which of the 8 holes on the evap case it was supposed to be used on, but they had no info. Cardo tells me neither of his 66 cars with AC have this stud(Pontiac and Freemont assembly plants). I thought at first that the stud and nut might be intended to go in a hole that had a shallow depression surrounding it like the attached photo. The problem with this theory is that all 4 of the holes on the RH side of the case have this depression. None of the 4 holes on the LH side of the case have it. Can anybody tell me where this is supposed to go?