Hi Merlin, PO here, those manifolds are a set of Red?s 36 mm with viton o rings for running mikuni?s. The bike ran a set of Red?s Mikuni?s and the rubber manifolds provided the insulation. With the mikunis?s she absolutely flew, even with the old electronics.
I too tried ultra sounding the dellorto?s, but they are shot, would not even run, so I junked them and bought the Mikuni kit from Red. That?s why the dells were in the box of dead bits.
Consider Mikunis as they are a much better carburettor and really give the triple motor a shot in the arm. Your inlet ports are approx 35 mm and stepped to Red?s 36mm inlet manifold so 36mm carburettors will work better than the standard 32 mm.
If you want to stick to dellorto?s then MarkQld has come up with a good solution, using a combination of new 36mm dellortos? with the original throttle linkages.
8)