I don't agree with a difference in these bolts. I hav 67 thru 70 b-bodies and they all use the same bolts for ballast, voltage reg, starter relay. No mark In the head, no spinning washer and no teeth on the underside. See picture. I have LA and St Louis cars 67-70 all use these bolts. Those anchor bolts with washer and teeth are newer.
There are definitely 2 different bolts used between 68-69. The ones you have pictured are typical 68 style. You are right about the anchor marking ones being newer. I should have caught that. The anchor ones are identical to the original bolts other than the head marking. Original 69-70 bolts actually had a head marking that looked like a target almost. You can kind of see it in this picture on the ballast resistor and voltage regulator. The engine ground uses a different type of bolt entirely. (5600 original mile A12 69 1/2 Super Bee survivor)
