Clutch issues. Can't put gear in while engine running

Yes, the pilot is an interference fit; when right, it needs to be lightly driven in. Get a new one and try it but if that is loose too, then something is going to have to be done to machine an oversize pilot bushing, or take out the crank, have the pilot hole turned oversize, and a steel bushing pressed in of the right ID to receive the pilot. Or put in another crank.

There may be another trick way to to do this: just don't know it. I can't see how to use brass shim stock around the pilot as it will be too thin, unless you turn the OD of the bushing down to allow a thicker, stiffer shim material to be driven in along with the bushing.