I removed the fenders from my '72 Challenger and had a few bolts that were a little rusty and crusty. I thought I'd pick up a fender bolt kit and soon realized not all these kit's are the same. According to one vendor 72-74 E Bodies and AAR/TA used upper fender studs. Mine had 3 studs along the top of both fenders and 2 studs on each side on the lowest section of the fender where it meets up with the door. Is this something Chrysler just switched up because of different bolt vendors? Or were the studs to help with fender alignment since they were a tad longer and could fit spacers on them easier? Here's the kit I had mentioned.
http://rtspecialties.net/proddetail.asp?prod=1000076B

As usual this is another case of documenting what your car originally had... I've seen at least 2 mabe 3 studs per side on the top and at least 1 but commonly 2 studs on the fender bottom...It all comes down to the assembly line installer and the crisis of the day... The studs made hanging the fender much easier hence the reason for using them but any combo of bolts and/or studs would have been possible...Here we are 40-50 years later and the resto community has drawn conclusions as to what's "correct" in the name of selling kits to make it easy...

My '71 and '73 Challengers had studs and bolts along the top edge of the fenders. The 71 is a june built car.

Thanks for the responses guys! I can see where the studs would have made it easier to hang the fenders.

My June built 1971 Challenger has the studs. I have seen some Challengers built at this time period that do have studs and some that do not. You would have to enlist Chrysler to when their breaking point was for the 1971 Challengers with the studs. I have found that Plymouths did not do this at this time. I believe the studs were used to eliminate personal having only one person take the fender from the fender line and place it on the car.

Thanks for the response hemicar1971, good info!

I was at a car show this weekend and did take a good look at as many 71 E Bodies built in May and June that were there. It seems that it was a change with the Challenger at some time at the very end of May, maybe the very start of June due to a lot of Challengers like mine for reasons were built around 10 days later than the Build date on the tag. There was a 1971 Challenger I looked at top to bottom that did not have the studs, it was a 407xxx serial number. The owner was sure the fenders were changed but the inners were not. So when being restored before he bought the car maybe someone changed the studs to bolts or maybe it never got them. This June Build Challenger had both front and rear bumpers with the slots and the 1972 trunk floor with the access hole to the rear shocks that faced the back of the car. It also had a hook for the jack and not a slotted bumper jack like in 1972.

WOW, thanks once again hemicar1971 for the info and detective work!