well i am from WI, but i know that our requirements enforce at least one mirror, turn signals, Speedo, and some other little stuff. you could change Speedo and not have to worry about the odometer. just make sure to note when you resell it that odometer does not reflect actual mileage.
I once had a punk ass shop that tried to "fail" my inspection because I have after markent rear turn signals on the bike that they said were not DMV approved and tried to sell me a set. I pulled out the regulations and told them that my bike was older then 1985 and the "or" in the regulations says I don't need turn signals at all; therefore, I was going above and beyond the regs and to pass the dam bike so I could be on my way. He did. Moral of the story is even if the regulations say you don't need it, the yahoo inspecting your bike may be clueless...so bring a copy of the regs with you.
Check this out. http://www.amadirectlink.com/legisltn/laws.asp
This was one site I found but some things were differnet from another site I found like WI didn't require turn signals and that it needed a speedo. I say if you don't drive like an ass then your pretty safe on not getting pulled over and having the heat giving you heat about what your bike is missing or what's illegal. My bike only has a headlight and brake light and one mirror and it's not even on the correct side but I never even got a eye raised by The Man. Hell and even the brake light isn't a three way bulb so it's only lit when it's activate.