don't know if this is the best but R/T Speciaties lists these
2026001 BODY PLUG KIT, 70 BARRACUDA 39.00
2026002 BODY PLUG KIT, 70 CHALLENGER 39.00
2026015 BODY PLUG KIT, 70-74 A-BODY 29.00
2026009 BODY PLUG KIT, 71-72 B-BODY 37.00
2026003 BODY PLUG KIT, 71-74 E-BODY 39.00
2026016 BODY PLUG KIT, 73-74 CHARGER 39.00
http://www.rtspecialties.net/miscell.htm#BODYPLUGS