brake line tube nuts come in 2 types for each size
one type has no lead in to the thread
the other type has a lead in before the thread, a smooth area from the end before you get to the thread.
this is probably an SAE/Euro/Japanese standards thing....
chrysler in just about all cases used the type with no lead in, this is due to the chosen style of pipe flare and what the tube nut was screwing into.
you can get both to screw into most chrysler parts but the lead in type are then only held in by 2 threads....which is no good, i.e you need the correct NO LEAD pipe nuts.
the only odd fitting is one of the master cylinder fittings and its bigger than all the rest I guess to stop you plumbing in the rear circuit into the wrong end of the MC. it bolts into a deep recess in the master so i guess either type with the right size thread would probably work here.
ebay and walmart style kits of pipe and a bag of tube nuts and fittings invariably are the lead in type that you don't want.
a brake place or well stocked parts store should have both types
the nut type and what you screw it into are a pair and its related to the style of flare to be used
|NO LEAD nuts shown here
45 Flare Sae Inverted Flare Tube Nut Fitting for 3/16 Brake Line Tubing 16Pc Set | eBay UK?
nuts with the lead in that you don't want here
3/16" 12Pcs Brake Line Repair Female Union Inverted Flare Tube Nuts Car Bike UK | eBay UK
Dave