WOULD IT BE A SIN

Do it !! Shoe Goo them on as they are non functional reflective only. Not harm no foul.
What do you mean by “non-functional- reflective only”.
68s are the opposite, - functional & NOT reflective.

I am partial to 68s myself,
That said- there is inherently a safety factor with having more illumination on your car, and as far as lights, I think the 68s are the coolest of the Mopar side lights.
On the flipside, the 67’s have a lot of one year only uniqueness to them, and the side panel does have a “cleaner” look without any lights/markers/reflectors.