Oh yeah for sure Craig, went from 12.9-13.0 with Elites 15s to 12.4 with the MPD 15s, no other changes, just nozzles. Then dropped another .2 with the addition of the 72 atmo. Pretty sure I have it in another thread.
Edit: found it!
http://powerstrokearmy.com/forums/showthread.php?t=43722