Use a lathe file to taper the oversize bushing slightly where it will fit about halfway into the hole with a firm push with your thumb, and use green LocTite "stud and bearing" compound to keep it tight in the crankshaft bore. Even if the hole is a little egg shaped, the liquid will even things out as it cures. I've used it on big wrist pin bushings for Cummins Diesel rods and never had one come loose, to the best of my knowledge. That's a lot more stress than a pilot bushing will ever see.
Jerry
