I have four 1 inch intakes with 3/4 inch pipe nipples with caps on three of them. The fourth has the ball valve. The 3/4 inch nipples fit tight in the 1 inch holes. You are right about the combustion rates.. the lump definalty burns hotter, that might be it.
The drum pics I have are from before I adeed the pipe nipples and ball valve. I was adjusting the airflow with magnets prior to the caps/ball valve.
Thank you for the compliments on the tenderloin and the help w the UDS.