No there should not be "a lot" of play in the pilot bushing. It should be a press fit into the crank and a slip fit onto the nose of the input shaft.
If the transmission changes; i.e. going from a T-18 to a T-176 the bearing should also be changed as there is often a different diameter on the nose of the input shaft.
Sometimes the inside to the bearing is also worn enough to allow slop between the input shaft and the bearing, in this case the bearing should also be changed.
...a well prepped, well driven, vehicle should do well in any terrain, including the highway.
Carburetors became obsolete during the last century... do what ever it takes to get fuel injection...It makes bigger grins off road.