One carb Triumph Head

Do the mid 60's Triumph heads only one intake port for a single carb and two for duel carbs, or is it done with a manifold?

Thanks.

Do you mean 350/500, or 650?

If 350/500, then it's basically down to the manifolds as the heads have twin intake ports, however for the 650 it isn't so simple, the single carb 650 heads also have twin inlet ports with a bolt-on single carb manifold, but the 650 twin carb heads have splayed inlet ports with screw-in inlet stubs.

Thanks L.A.B.

Dont't know if it's relevant, but you can squeeze two concentrics in parallel onto a single carb 650 head.

Yep, there are several manifold kits to convert a single-carb TR6 head to dual carbs, side-by-side AND splayed.