hello i have a lt500r quadracer i just put a new fmf fatty and powercore silencer on it and i would like to know what jets to run with this pipe i am at 900 ft above sea level i need a good starting point with this set up if any body know much appreciated

 

I also have a 87 zilla with a bills pipe, 41.5mm bored stock carb and open air filter. I run a 410 jet at sea level and 400 jet at 300ft. I would start at either 400 or 390 and work down.