Could the Burma Road become a railway into China?

If Singapore and Malaya held and the Fourteenth Army entered China, could the Burma Road be converted into a railway?

A mapped narrow-gauge route was plausible and would improve supply, although mountain geography and limited capacity would constrain it.

The counterfactual keeps Singapore and Malaya in Allied hands and sends the British Fourteenth Army into China. A railway route had reportedly been mapped, although the Himalayan geography made any direct alignment difficult. British experience with steep and narrow railways makes a narrow-gauge line more plausible than a standard-gauge main line. A later exchange suggests the route might wind through easier terrain or approach through Indochina rather than cross the highest mountains directly. Its carrying capacity would remain limited, but it would still improve greatly on the available road supply.