in a normal glow engine the front bearing carries no thrust load unless it's used in a pusher configuration or being slammed on with an electric starter, in normal use the rear bearing carries the thrust load. tapered roller bearings are used in pairs and require a spacer between the inner races, this would make a very expensive engine. standard ball bearings carry this small thrust load just fine.
the needle bearings on gas engine con-rods are the simple uncaged type that serve well at low engine speeds, for high speed glow engines a caged needle bearing would be needed but the main problem is finding room in anything smaller than a .90 .

dave