Some of the 91s did not like puffer, not enough pressure, I have one of those. The only draw back of pipe pressure is that you have to be carefull to not pull the power back during some manuevers. If you where to pull the power back in a split-S after you got the nose pointed down, the higher pressure in the fuel tanks would push fuel back through the vent line into the pipe, and with the nose pointed down that fuel might go back into the engine and put the fire out. I have allways felt it was easier to set the needle on a pipe pressure set up, it was more controllable on the rich side. It will really come down to how well your engine runs on puffer as to if you should use it. If you have trouble getting a reliable rich setting on puffer you might want to try pipe pressure.

Steven