Trunk Ground Location 1971 DART?

...........And don't forget these girls changed through the years. I just yanked A/C out of a junk and I mean JUNK 69 Dart HT which is hopefully gonna be the donor to fix the roof on the 74 Scamp. There is a brown ground wire associated with the heater grounded to the bracket retaining the heater hose nipples RIGHT UP AGAINST the inside firewall. No hope!!!! Of getting to THAT with the heater/ AC in place!!!!