1)Call macs products or google products in San Jose Cali
2)He makes simple 90 degree bends that screw in , you then add exaust tubeing(screws ins ) and you can even add your stock muffler on the end of the exaust tubeing .
Look up warbirds and look for "My second VQ P40 " I have this set up shown in pics with my OS 91 .
You can even tap the 90 degree bend so you can add your pressure fitting and presurize the tank