You may be able to find a company that will allow full coverage (comprehensive and collision) on a salvage title car but it will likely be pretty difficult to do so since it is already hard enough usually to find any insurance company to cover a salvaged car. Most insurance carriers that do insure a vehicle that has a salvage or rebuilt title only allow liability coverage to be issued for it.
Insurance companies tend to not want to insure a vehicle with a salvaged title due to the fact that it means the car has already been in a prior accident and thus not in top shape so it may not be able to provide the safest ride in the future. If you are looking for full coverage on a vehicle, check with your state's insurance regulator to see if in your state this type of coverage is available on this type of titled car. If it is, then the insurance regulator may be able to help you find an insurance company that offers it in your area.