I may be in left field here, but looks like aluminum header is for a Westbend 820. Hard to tell without blowing up the pic or a closer shot of flange.
With such a long elbow, almost 180 degree bend, the pipe could be aftermarket for an older dirtbike. I dont recollect seeing anything similar to that for karts. But I could be way off base. There were some oddities in the early seventies.
pipes off a chapparail 80cc mini cycle supposed to be on a sachs motor but its got a west bend 820 header cobbed on the end ..they put same motor on early bonanza mini bikes its possible the go powers went to a bonanza befor they switched to hodoka ace motors and kidney bean wheels ..
ic . well im almost posative pipes off chapparail mini cycle its exact same as a rupp 80cc mini cycle .. i just sold a couple motors to bill the mini bike guy in ohio ill see if i saved the pipes .. P.S. got your Pm. thanks for relaying message all is well ...