Using rootexplorer go to "system"-->"customize"--->"resource". Look for a file with "bootanimation.zip" in the name. When you find this move it to your sd card. Now find Ultra's bootanimation and change the ".zip" to ".old" (or just move it to your sdcard). Now move the bootanimation you want from the sd card back, and rename the bootanimation to match the name of ultra's bootanimation. Haven't tried with these particular roms but always works for me.
Some names I've seen: Sprint_bootanimation.zip(meanrom), SPC_bootanimation.zip(Stock)
