These are the correct right and left inlet manifolds for the 1969-1971 Triumph T120R model. They feature the pressed-in carburetor mounting studs and threaded ports for the balance tube stubs.
The inlet manifolds are threaded in the correct Unified thread form for fitment into the cylinder head. The integrated carburetor mounting studs are threaded for use with 1/4-28 TPI UNF locking nuts.
The inlet manifolds are threaded into the cylinder head intake ports and secured with locking rings. The balance pipe stubs are fitted to the ports on the manifolds and joined with a rubber hose. The carburetor mounting flange is fitted to the corresponding flange on the manifold.