i recently killed my banshee on a trail ride with some friends so i finally had to break down and get everything together for a rebuild. while doing so a friend of mine offered to make a me a deal on his top end off of his banshee since he was about to put his race motor on that frame. the top end has maybe 2 hours on it and it was priced right. now to my actual question after my ramble. my new set-up includes a stock set of cylinders that are full race ported (not triple ports) with 68.5 mm pistons.
i am trying to establish a safe baseline to start tuning from. in memphis i am at approx. 350ft above sea level, i am running the airbox with lid, snorkel removed (of course) k&n and pro-flow adapter and stock carbs. what main jets should i start with 320? 340? what needles at what position? i know th air box and lid are power robbing but when i ride in the woods with my 4x4 friends the air-box and lid are added insurance in the water and are help full for a little extra throttle response. any guidance or suggestions would be appreciated.

thanks
Donald