Alan,
Attach an old 5/16" BSF head stud onto the tapped end of the kingpin and stick it in your lathe or drill on slowest speed,apply lots of engine oil to pin and bushes in the stub axle and gently (very gently) feed the stub axle onto the pin. Be prepared for it to grab so be very careful. Keep pulling them apart and adding more oil. My dad showed me how to do this. He was a fitter for over 50 years.Please be careful!
Dave.

Location: Sheffield

So basically lapping in the king pin, just not with a grinding paste just with engine oil?

Location: Northumberland

Has anyone found the original specs for kpins? I suspect -.001 to run in a standard .5 inch hole, although new reamers are usually a shade oversize and may cut accordingly. All the very old used and new kpins I have are under .5 inch.

So many axles eyes are loose a shade extra pin diameter is useful.

The kingpin may distort slightly when in the axle so a super close fit in bushes before can prove too tight and awkward to fix if the pin chances to be very tight in the axle. Must be free in car; loosen eventually but car will wander meanwhile and risk of bushes turning in hubs. Abrasive materials tend to bed in the bronze and cause ongoing wear.

Trust you have perused most of the previous kingpin posts.

Location: Auckland, NZ