Hi Al; Here is a scan of the Poulan 46 gasket for the header. I used 1/4 thick 6061. The holes are .250 dia. The center to center on the holes is 1.450. The width of the port is 1.000 and the height is .650, of course the odd shape
If you could crank out some flanges I could make you up a header or muffler or???
Thanks; Adam