3" Xpipe to 2.5" tail pipes?

I read some place that reducing the size of tail pipes didn't have a big effect on the performance. Think it had something to do with the exhaust gas temperatures cooling off father back in the exhaust system.

At our local track there was a guy running 10.00et at 135mph in a 1965 Chevy 2 street car. It was a small block with a small B&M blower and a nitrous kit. He was running 2.5" pipes to 2.25 mufflers & tail pipes out behind the 9" tires.

The smaller tail pipes didn't seem to hurt his performance.

Edit: Here is a write up on the car. The owner was unfortunately killed a few years back in a offroad accident. This car was something else to watch in the quarter mile and he drove it everywhere. http://www.hotrod.com/featuredvehicles/hrdp_0405_1964_chevy_nova/