I learned the hard way to buy the parts as your ready to use them
Just in case you want to return someting or happened to order the wrong part.
Sometimes if you order parts to early the return period will pass.
Ive actually had rubber parts go bad sitting in the box before I had a chance to install it.
But then again it took me 3 years to do about 4 months worth of work.
Take my word for it.....Im an old ex shop 38 submarine mechanic. Nuc/Non Nuc

I thought the kingpins were floating type?