For anyone doing it themselves in Colorado, here's some info to work with for conversion registration.
Administrative Procedures
Statute, registration where
Take note of statute (2)(b)exception !
Damian

Did you successfully register a Class 8 as a motorhome in Colorado?

Hi Silvius,

I've made arrangements to do so with a specific person in DMV. My plates need renewal in April. I don't expect any difficulties since the dmv rep has done one in the past.

Damian

Thanks for posting this info, did you look into registering as a recreational truck?