Backfire through Carb!

Long story. Working through a series of problem but the hot topic is the moment is the carb seems to be running rich and back firing through the carb at about 2500 rpm. Have checked all vac lines and will recheck again. I know that ALL OF THE CARB ADJUSTMENT SCREW HAVE ..sorry about the caps. been messed with before I owned it.

Have reset timing to 8 BTDC...have set idol speed to 750 RPM with my tac. What should I "Adjust" next.

Ok...next dilema. Started checking vac lines and found nipples broke off Thermo valve and AAP Thermo valve. Any idea where to find these part? Any yards specialize in old Ram 50?