The Dyno charts show that the 264/272 set up makes just a little bit more torque and horsepower than the 264/264 . When you go 272/272 you lose torque. But gain like 1hp over the 264/272 when running to 6800-7000 rpm. So it seems for a good street setup up the 264/272 combo is ideal. I have an automatic so i am concerned with low end torque as well as top end power.
http://www.automotosports.com/cam_test.asp