[busmania]

Thank you! 7/16-24 is what I thought but wanted to be sure.


Updates

-Rear axle nut - 5/8 x 18
-Steering column nut - 5/8-18. Standard 5/8 UNF thread.
-Female rubber brake lines - 7/16-24

Thanks to frnkeore above for this helpful info in head studs.
Regarding the stud holes for the head, they are tapped to .0025 under the nominal pitch diameter and the drilled hole is to be between .349 and .353.

The proper tap will be 7/16x14 H-5, where a std tap is 7/16x14 H 3. The last number is the nominal size +/- .0005 so, the -5 means it's .0025 under size.

But, you can clean out the threads with a grade 8 or Allen bolt, with the first threads shaped like pictured.