Screw in trim posts.

[Rdchallenger]

Are they normally self tapping or is a pilot hole needed? What size bit of so?

[7E-Bodies]

Which trim posts? Perhaps I could measure mine for you.

[Rdchallenger]

The ones for the vinyl top trim as well as windshield trim. These are what I bought.

https://www.ebay.com/itm/30-pcs-4-x-3-8-Chrysler-Dodge-Mopar-vinyl-top-side-moulding-clip-screw-studs/191217884174?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D40741%26meid%3D1c0e5059c8264145940fd6eaa9782eed%26pid%3D100675%26rk%3D2%26rkt%3D15%26sd%3D333322668041%26itm%3D191217884174%26pmt%3D1%26noa%3D1%26pg%3D2481888&_trksid=p2481888.c100675.m4236&_trkparms=pageci%3A892356e1-d754-11e9-9944-74dbd1807373%7Cparentrq%3A32719a5216d0a4b7b6dfcdbaffa473be%7Ciid%3A1

[70 Challenger Lover]

I would say a pilot hole is needed for sure. As far as the bit size, you will need to hold the bit up to the screw. The bit must be at least as large as the screw diameter portion at the bottom of the thread. Because you are going into metal, you probably need a slightly larger hole. I'm guessing around 1/8" or so. Start small and try one. If it is excessively tight, remove it and drill one size larger.

[7E-Bodies]

I thought the vinyl top trim and the windshield trim were totally different. Perhaps only on a 70. Am I wrong here?

[70 Challenger Lover]

I thought the vinyl top trim and the windshield trim were totally different. Perhaps only on a 70. Am I wrong here?

They are different for sure. The front and rear window trim clips are held in with small screws that have a little bit of sealer on the threads. The early E body cars had holes for the vinyl top trim and the clips had studs held onto the car with nuts on the backside. The later years had studs welded to the body with plastic clips that attached to the studs. The screws displayed look like they will work well as "studs". Personally, I like the earlier ones with holes and threaded studs because it would be much easier to remove the trim later if you needed to. On the studs, I imagine you would snap them on and not be able to remove them again without needing new plastic clips (which I guess is not a big deal).

[Rdchallenger]

I thought the vinyl top trim and the windshield trim were totally different. Perhaps only on a 70. Am I wrong here?

They are different for sure. The front and rear window trim clips are held in with small screws that have a little bit of sealer on the threads. The early E body cars had holes for the vinyl top trim and the clips had studs held onto the car with nuts on the backside. The later years had studs welded to the body with plastic clips that attached to the studs. The screws displayed look like they will work well as "studs". Personally, I like the earlier ones with holes and threaded studs because it would be much easier to remove the trim later if you needed to. On the studs, I imagine you would snap them on and not be able to remove them again without needing new plastic clips (which I guess is not a big deal).

Correct I have a '73 so all of mine are the studs instead of the screw in style.

[7E-Bodies]

Thanks @70 Challenger Lover, for the clarification. The holes seem much more user friendly. My 73 Barracuda had the studs.