We were able to get this one made on the assumption that the DT360 and SC500 were essentially interchangeable with the exception of head pipe diameter. He built the pipe to fit his 360 with a neck down at the cylinder to fit the 360 flange. Then he chopped off the 360 sized portion and welded on a 500 sized inlet. Pretty slick.

Ordinarily you have to have the bike there to make a new pipe. You might check with Jemco, there is a chance they have a jig and a design for your bike already.