Am replacing an old oil furnace with a new Bryant. New units come in 2 sizes (each with three firing rates). Luck would have it that my required size of 90K btu output falls smack in the middle of the two (smaller unit max output is 85K, larger unit min output is 97K). My contrator recommends going with the larger unit -- says it can be fired below 97K output by putting in a smaller nozzle (.75 gph for 85K) if necessary (the Beckett burner is the same in the big and small unit). I'd appreciate any insight re the pros/cons of doing so if the installation at 97K is oversized. No a/c involved, just heat in a mild climate. Am also replacing some v.old ductwork, so will be picking up efficiency enroute from the basement to the registers.