hey I rebuild dodge diesel trucks, ive used several hemi powered trucks for their bodies. several grounds on setup which u probably forgot to remove the one from your bellhousing(drives side top to firewall or bodies floor pan/heat shield bolts.
if I remember correctly, there is the mentioned above, ground wire on corner of your ecu attached in same mounting bolts as ecu, tranny ground.
any 8-12 ga wire wire gormets will give ample ground you need.
2007 jeep grand cherokee 3.0 crd limited,gde eco tune with dpf delete,mbrp dpf back exhaust,255 falken wild peak AT's,propane injection for fuel economy
2006 dodge ram 2500 megacab diesel,long long list heavily modified 545hp,1090 ft/lbs of fun:)