As a club competitor that may have occasional difficulty with getting a navigator am i able to run a Super 1650 in Prolite class on those occasions i cant get a Nav or is this a log book headache.
There is absolutely no problem with it at all. I had to do it a couple of weeks ago to race over here in SA. Seat and Seatbelts need to be removed from the navigators side and change the number. You may be lucky enough to only have to change the first digit of the number.
You could probably even bolt a turbo to the frame and run pro class as I don't see in the rules where the turbo has to be connected to the engine or working.