I have used a red Millers Deltaplex 2 EP for many years and got 40k out of my first set of kingpins. Reading up a bit more on this it appears that high temperature is also a factor in encouraging the sulphur content of EP greases to attack bronze. So I think king pins are fairly safe in that respect.

Doug
2011 Plus 4 in Rich Maroon

1972 750 “ComDom” sprinter
1958 Triton 650
1992 Triumph Trophy 900