Looking at several original flip top assemblies I have and I notice two variations. One style has the metal tab screwed in place to pop the lid open. The other style has no provisions for the tab and instead uses a rubber grommet to pop the lid open. My originals have one type or the other. My assumption is that if you had the metal tab you wouldn’t have the rubber grommet. I’ve seen pics of restored cars with both the tab and rubber grommet but don’t know if those just got added during restoration.

It is my understanding that all Challengers optioned for the flip top cap also came with the locking gas cap. The locking cap does mate up well with the rubber grommet causing the flip top lid to pop open.

Anyone know if this was a design change, early vs. late thing?

ALSO... any recommendations on how to remove and replace a chrome flip top lid? I’m not sure what to call that pressed in pin, or how to get it out without damage to the lid.

that pin should just tap out with a pin punch. those punches are made with a ball on the end to center the punch in the hole of the pin.
i would put the cap in a container of your favorite penetrate liquid for a couple days to ensure a little help with tapping out the pin.
if this pin is NOT able to be removed as i stated, someone please correct me before floyd damages his cap due to me giving him bad info !

When I had my Challenger flip cap re chromed, I punched the pin out with a drift, I replaced it with a stainless steel roll pin....if your having the caps re-chromed use a smaller dia pin due to plating build up, or ream the hole slightly larger before chroming...to reuse your original pin

Mike

here is the cap off of my mid-July '70 Challenger R/T

I believe it is the original - even has some "Earl Scheib GREEN" overspray on it

rubber seal to locking cap - no helper spring - blind roll pin at hinge & release (so it can't be seen from the top when mounted on a car) HOW TO REMOVE IT?

the "Locking Gas Cap w/Flip-Top" was the only OPTION, $4.40 in '70 ( not available separately ) & it was discontinued during the '71 model year

Thanks for the replies. I drilled and tapped the roll pin for a 4-40 machine screw. I need to run out and get some 4-40 screws and will try to pull it out/tap it out that way. I’ve been soaking it with kroil. Will report back with results.

Run the 4-40 screw (with a washer) through the ratchet end of a 1/4" drive socket.
Then thread the screw into the roll pin. As you tighten the screw the socket should bottom out against the frame and as you continue to tighten it will draw the pin up into the well of the socket.

Used same method to pull blind threaded dowel pins on machinery all the time.

Great suggestion. Thanks!!!

i didn't realize it was a blind hole, and the above suggestion will work. i have done so many times as well.
soaking will do wonders, as you are doing.