I don't know anything specific about the socket # you reference above, but most of the repro houses for these cars indeed sell a 2 wire replacement socket, which is incorrect for the car if you're a purist, but is guaranteed to have a more consistent ground than the original if properly installed. In fact some of us who value performance over originality have put effort into running a dedicated ground wire to all of our lights to permanantly eliminate all grounding problems back there...and the new 2 wire units like these will take much of the hassle out of such a mod: http://www.classicindustries.com/firebird/parts/a13558.html
Rock Auto sells the same replacement for $2 if you want to save a few pennies, they charge less for shipping too on small orders.
i had to rewire all of mine in the rear. i went to baxter with the original parts. i found a aftermarket replacement that was a one wire unit which fits the original light socket. just the color of the wire and socket are different. it works great
I bought these side marker light sockets for my 68 Firebird and there just like factory maybe better. ebay Seller: sniff-out-parts item # 150975159601 active listing 1-04-13 They light up and fit perfect in the housing!!
