Stock Alltel Rom on unlocked phone?

[h20]

I have Olipro 2.40 on my phone and radio 3.35.04 and using the ppc kitchen for ROMs. I have read that you can never go back to a non-gps rom once you have a gps rom on your phone. The newest Alltel ROM has a post 3.35 radio but not a gps rom. Can I install the whole Alltel update or should I run it up to the customizations and install my cooked rom or just go straight for the newest sprint radio and cooked rom? My coverage seems to be spottier and drops evdo in more places and since I listen to music streams all day it gets rather annoying. I thought a newer radio might help. I have the latest alltel 30031 prl.