It should not.
The primary ground for the chassis is by way of the braided strap from the firewall to the cylinder head - the direct chassis ground is secondary. However, it does help to have it somewhere near the same gage as the primary ground (I believe the braided ground strap works out to be about a 10-8AWG or so...) in the event it becomes contaminated beyond utility.
Adding that chassis ground is one of the small number of things that ChryCo engineers did that I like - AMC should have done it, but they never really have on anything (that I recall. Odd...) It was less of a problem with points & condensers, but the electronics make it critical to maintain a solid ground return. That's why I've got it as an option on RENIX kits.
More critical is to make sure you clean the contact patch for the lug (and the lug itself, if need be) down to bare metal and apply a corrosion inhibitor like Ox-Gard (find it - or something similar - in the electrical section at your local hardware store. Please, for the love of Gawd and all you hold Holy, do not RPT NOT use WD-40! It is not and has never been intended for electrical use, and it will cause more trouble than you're trying to correct!)