I use 4 1/2 inch valves and originally used 4 inch nipples. Worked real well but changed over to 1 1/2 inch nipples and it really made a big difference. Seems like the oxygen drew the fire out toward the outside of the basket better with the shorter nipples and burned much more even. Just my $.02.
my avatar swiped fatties from the plate....look how sorry he is.
NB Bandera with mods
Weber 22 .5" x 2, 26.75" x 1
UDS x 3
Created "The Great Spam Revelation of 2011."