I hope to finish up all the "small stuff" on my '21 Touring tomorrow. There are a few places where I don't have the proper bolts with castle nuts and cotter pins. These places include the lower steering column to frame mounting, where the wood block goes, and the oil pan ears to frame attaching points, also where the wood blocks go. I'm thinking about using the right size bolts and nylon insert locking nuts until I can order the correct stuff from Lang's. What do you think?
Fine with me, I won't tell.
Betsy came with a bunch of those, they hold well. I have been slowly replacing them with the correct hardware as time and motivation allows.
I use the nylon insert locking nuts in several places including the bolts that go thru the wood blocks for pan ears. My car is a driver so am not worry about 100% correctness. The long bolts that go thru the wood blocks for the pan ears are hard enough to got to, esp the drivers side with starter that I bet once you install them there they will stay. The others aren't so bad.
Langs ships fast. If you aren't in that big of a hurry, just wait. If you have a pre '14, you will want the castle nuts with square bottoms to be correct. Don sells those castle nuts cheaper that I can buy them at the local hardware store!
In most places unless you want the appearance to be original, they will work very well. On the wood block, a self locking nut would be OK. You don't want to tighten it too much because it could cause the ear to crack. the bolt actually just holds the wood from slipping out. The wood itself will hold the crankcase arm. The top bolt which goes through the frame should be tight. Also the bolt which holds the steering bracket, the one which goes through the wood should be self locking if you don't have a castle nut with cotter pin on it, because the wood can shrink and cause the bolt to get loose and a regular lockwasher would not be good there. Also nuts on the steering parts and on the wishbone bolt should be castles. The wishbone should be wired because the studs can come out even if you have cotter pins.