Is this what One looks like? 70mm x 63mm BxS:
Special Cast Cylinder Block anchored with 10mm Studs, Arias pistons, Knife-edge Crankshaft, narrowed Alternator Rotor, Peened and polished Rods, Stainless valves, RC315 camshaft, Martek Optic Triggered Ign, Mikuni 29mm Smoothbore carbs, Holes drilled everywhere etc. This does not look like a "kit" to me? I t came with a "off a wrecked dragster" story.
And yes, I agree that 1400cc is a bit of a stretch, pun intended. But This engine sort'a found me, maybe you found yourself one. I emailed Russ but I don't think he bothers with that motorcycle stuff anymore, that was 40 years ago.. You can call him. He was still kikin just a few years ago building Fuel Injectors.