Achipmunk, yes, you make sense. Your second paragraph describes my error: I have been trying to screw the brake line into the hole that takes the banjo block retaining bolt, which are different threads.
Interestingly, my NAPA guy says my new WC, which I got from ClassicParts.com, is the wrong one. O'Reilly A.P. sells the exact same one for the '51 1/2 ton. Very confusing.
I will check Advance A.P. for the banjo block. Thanks!
