Cut the flanges of the old set of pipes and construct from there.
or Builtwell sells a complete build it your self kit with all the flanges and pipes youll need.Alot of people i know used it and its A-1!!
You need EXHAUST VELOCITY. Backpressure is created by baffling.
The diameter of your pipes are as important as the backpressure. Short pipes, even at 1-3/4", generally cause too much cylinder heat to be effective and take away from bottom end/midrange torque. Their only values would be at high RPMs......
There are other options though.... Torque cones, Internal restrictors and of course, longer, but cool pipes. :thumb
well i guess i will wait till i fet it almost together and then work on the pipes to see what looks good.... right now im alittle unhappy i was told the frame had a 40 rake.. and its only a 34... i dunno what it will look like now