Just finished parting out a truck that was rolled pretty good and the owner told me the axles and birfs were stockers. After pulling them out they look like they have been heat treated (bluing on the ends of the inners and around the bell of the birf) and was curious if these were actually an aftermarket version. On the bell of the birf it says "100 AC Birfield - NTN WH 5 (could be an S instead of a 5). I dont recall the stockers i have in my truck being heat treated but its been quite a while since ive had them out.

Thanks!

Pics:
[Linked Image] [Linked Image]

Red 1996 S10 Zr2 (Semi-Retired Wheeler)
'84 Toyota on 36's (Project in the Making)