Originally Posted by 71TA
Dug this off my own 71 Challenger. Must have been a bad day "on the line" was only ONE of these holding my plastic t-bar splash shields on.

Looks like 1/4 x 7/8 Type AB (AB is the pointy tip and fine threads) 7/16 hex head 5/8 washer





Got a better pic of the head markings ?