Just do a search on the OS 1.60, The Pitts is necessary and with the pitts you have to have a pump, the pitts does not make enough pressure to give the 1.6oz/min of fuel needed at full throttle. on the bright side the 1oz pump helps with balence. Some may argue that the cline regulator is better and it may be, but I have no expierence with it. My tank is over the CG, Some people have had luck by placing the tank behind the firewall and plugging one outlet of the pitts. One word of advice, burn-in the 1.60 on a test stand w/o the pump and with one outlet of the pitts plugged, It is much harder to burn-in with the pump/engine on the plane. I learned my lesson the hard way on that one.

Dan