1) I use the donut only on the exhaust pipe to manifold. But I suppose it might depend what sort of flange your exhaust pipe has.
2) Intake to exhaust union - I think there is a torque spec in shop manual. I would have to look it up.
3) You will need the clamp thingee anywhere the exhaust and intake share a bolt between them. I never had a good way to use a torque wrench there, so “tight” was good enough.
4) I don’t have a gasket between my Bakelite spacer and the manifold, but I don’t see what harm it could do. Don’t sweat the carb nut torque. Just nice and snug but don’t go gorilla and break or warp anything.
