Ok, I thought you meant it was a big rubber strip on the underside of the bumper. You are describing the little pieces of rubber that are like the license plate rubber stops that keep the license plate from rubbing? Here is what I am talking about: https://www.autometaldirect.com/bumpers-license-plate-bumpers-c-24_293.html

I restored my front turn signals awhile ago and I don't recall there being a small rubber bumper underneath...hmmmm. The car is at the shop still getting finished but I owe them a visit. I will have to take a look to see if the AMD bumper has a hole there for that. I sold my original bumpers and don't recall any details of them. I thought the front turn signals just had 2 mounts at the top for the j-nuts and 2 bolts.

I also just looked through my restoration books and factory service manual. Both do not do a good job with the front turn signals so I came up empty.

I posted this on www.69roadrunner.net See if anyone knows the answer.

Yearone has a complete body rubber bumper kit, they do not specify where they all go... https://www.yearone.com/Product/chrysler-b-body/bbk2#prettyPhoto