[sprint6ohc]

I noticed two different styles of the lens. Anyone know the history on these. One has fine lines, fins, on the edges the other is smooth. These one with the finn's was in a yellow and white box. The "smooth"one was in blue and white box.

[JimFB400HO]

There were two different housings in '68, an early two bulb housing and a single bulb housing. Could the different lenses be from the two different housings?

Pontiac Service Bulletin 68-I-17 dated 10/31/67 describes the housing change.

https://firstgenfirebird.org/f-a-q/d...sembly-change/

[sprint6ohc]

Thats what I was wondering. Could the lenses have changed with the two bulb and one bulb metal housing? The physical size of the two are the same its just the "look" has differences. Was this just a production/ supplier change?

[JimFB400HO]

I can't tell from your photos, can you see any difference between the transparent surfaces of the two that would enhance the light from one bulb to better illuminate both sides?

[north]

Never heard of this, since the service bulletin was so early in the year the change must have come very early in the production run. Was this on all Pontiac’s or just the Firebird?

I guess the change was to drop the separate side marker bulb?

[JimFB400HO]

Originally Posted by north

Never heard of this, since the service bulletin was so early in the year the change must have come very early in the production run. Was this on all Pontiac’s or just the Firebird?

I guess the change was to drop the separate side marker bulb?

From what I've read in old discussions; when the government mandated side markers for 1968's, Pontiac was unsure whether that meant that they were required to have a separate side marker light bulb. When they found out they could use one to light both sides, they issued the design change.

Sprint6, North brought up a point, could one of your lenses be for a different Pontiac?

[OG68]

IIRC even though they look the same, A, B, & F models all had different lenses.

[sprint6ohc]

Ill continue to check on this.

[north]

A, B and F were all different In 68 I believe but I wonder if all three had the double bulb version?

Similar variance in 69 Big cars for a different reason... seems like they were planning to use plastic front valance panels as a mid year switch so the later production cars used a parking lamp housing that incorporated a male packard connector directly to the metal body of the lamp housing. The plastic valance never made it to production So that extra connector was never put to use. There are several references to the plastic valence in the assembly manual and early MPC’s

Sort of the same situation with the 69 Tempest-LeMans (But not the GTO). A plastic valence was planned so a third wire and prong were used to ground the parking lamp housing. As it turned out the valance stayed steel so it wasn’t necessary but I guess it was too late to drop the extra lead from the forward lamp harness and the lamp socket. No mention of a fiberglass Firebird valance for 69 that I’ve seen.

[OG68]

From my Parts Manual, Section 2.589, Revised 4/1/68

F Body 5960532 - R, 5960531 - L

A Body 5960398 - R, 5960397 - L

B Body 5960072 - R, 5960071 - L

No mention of a different lens for the double bulb fixture but I wouldn't expect to see one either.
Interestingly, the parts manual (2.585) shows different part numbers for the double and single bulb assembly for the Firebird and Tempest but not the B body. So did the B body only have the single bulb assembly all through production?

[sprint6ohc]

Part #s definately all firebird. 5960532 and 5960531. See attached pictures of numbers and differences.

[sprint6ohc]

Better pic of part numbers on boxes