All of the things I was weighing on the bathroom scale suddenly got a lot heavier when I purchased a 700 lb hanging scale and 90 lb Postal scale.
On careful checking, it turned out that the bathroom scale was reading way low.
The hanging scale shows a standard 998 Vincent engine at right around 220 lbs with everything attached, carbs, exhaust, the works.
Other than the belt drive, I cannot see a good way to reduce the weight of the engine very much. It takes a lot of drilled holes to equal 1 lb. You could turn it to Swiss cheese and only take off a pound or two.
Chopping the cases would cut some weight, but you must add in some engine plate weight to get some kind of gearbox back on there.
The AMC trans is quite light, but it struggles to contend with the torque of a stock 850 Norton.
Do they hold up against a modified Vincent 1000 ?
Definitely wouldn't last behind a tuned 1300+
Maybe a 6k$ TTI would.
I think the 5 speed Quaife with its 200 HP gears in the Vincent cases is the best solution, although the end result isn't light.