Anyone know what the bolt size is for an original '71 rear spoiler (length, diameter, threads per inch))? Are all 4 bolts the same size/length? Thanks! Craig
Originally there were 2 studs with nuts, and 2 threaded screws. The nuts had captured washers with 6 fingers on them, like you will find inside doors for the window hardware. The screws were special fiberglass screws (I think they also used these for cement) The threads were not uniform, with 1 being short and the other long, so it would grab and hold the fiberglass and not rip it up. They also had a special insignia cast into them, and were not used anywhere else on the car. I don't think any of theses pieces, studs, nuts, or screws are available. Good luck with your search. Duane
The nuts will be 1/4-16 there are probably 20 or more in the doors in various locations with the captured tooth washer
I believe these are the correct ones. Marked Camaro rear spoiler. I am pretty sure I used these on my GSX restoration. They sell the bigger 5/16” gold nuts for seat mounting studs too.
"Maybe someone with an original GSX and spoiler could post a picture of the fasteners on the car ..." You're wish is my command. These are pictures of original hardware off original 70-72 "Factory Installed" rear spoilers (Not NOS). I took these when I was putting together the spoiler difference article. Many of these pics have never been posted before. Their veracity is without question. If you look at the "screw" closely you will see the higher & shorted threads I was talking about earlier. What you might think is due to rust, is actually 2 different types of threads on the same screw. Duane
Maybe someone could put this in some sort of reference section, as it basically answers everything. Duane
Its a self starting sheet metal screw. only requires a hole smaller than the screw by a little. Why didnt they just use 2 studs? Screw the screw use studs
Because it would require an oval hole ie harder to seal and harder to make the hole and that isn't a sheet metal thread GM used that same thread on the fiberglass header panels thru out the late 70's ~ early 90's
Body by Fisher would know the thread. But they are no more. You can call it a body thread. The threads used for fiberglass and plastic had different threads. more coarse. also had alternating thread heights/depths.
Those nuts appear to be the ones I posted from AMK. At least that puts you halfway there. The screws are Elco brand. The same brand used for the valve cover screws with the flag insignia on the heads. I know Duane. Some years.
