Perhaps the most common locknut for the 5/16" exhaust clamps are the version with zinc plated nuts AND washers. Go for it!  #1109

Wonderful reproduction of the always missing or damaged exhaust resonator hangers found on E-Body Mopars. Will work for 340, 383, 440, 440+6 and Hemi-equipped cars! Includes correct "center point" locknuts as used on the assembly line. Sold as a pair. #3404932-P  NO LONGER AVAILABLE. CONTACT ECS EXHAUST 760-793-0804.

Finally available are the correct fasteners for the E-Body resonator hangers to the floor pan support brackets. Assembly line "H" head marking along with the proper phosphate coated flat washers. Its all in the details!  #6022226-P