3" exhaust reducing down to 2 1/2" after x-pipe

Hi Brian, dad's wagon dropped a little bit (.05 sec.) running 2.5" mufflers but he still runs 3" over the axle pipes. His 4100 pound car runs 117 mph so you can run the numbers to see what sort of power this takes.
It's always a toss up when you need tailpipes to fit versus getting every last hundredths of a second out of the car. Dad wanted quiet as can be so we worked hard to keep the sound levels very low and the performance very high.
Tom