I have a suspicion that they probably relay on crankcase expansion as well. I cannot see any Indian engines being set up 'properly' for maximum bearing life, as it would take too long with the wide variety of tolerances on the machined parts.
Given that most of the crankcase is going to be CI and a steel crankshaft (I hope!) then the expansion rates are all much of a muchness, so it should be fairly simple to set it up within a though or two with gaskets, but it doesn't take into account bedding-in looseness and wear clearances.
The Lister crankcase is pretty rigid and would maintain good stability, but nearly all long-lived engines are fitted with plain bearings of some type or other, with notable exceptions for specific reasons. Little tiddler engines like the Villiers and Suffolk Punch lawn-mower engines are plain big-ends and ball bearing mains. JAP engines had similar arrangements on the industrial side.
Unusually, the early Petter engines had ball and roller bearings, even up to the larger atomic two-stroke diesels.
Peter