Running a mopar intake with the old DC mechanical 6 pack carbs. Rear half both pass and driver side plugs are very white compared to the front 4 which look normal to slightly dark. A/F meter shows about 14.2 idle- between 12.2 to 13.5 from off idle to medium cruise, hi speed cruise and highway is 13.6 to about 14.3. This is all of the center carb with 64 jets. With all 6 - WOT it's at 13.4. I have upped the jets, but I just think it's odd that the rear 4 plugs are so much leaner looking... any thoughts???