Locking Nuts v. FLanged Nuts

Stock type "sems" nuts with the built in captured washer, and serrations on the edge of the washer so it bites into the floor pan worked well enough for chrysler when these cars were new. So well in fact that i have snapped many a seat track stud taking them out because they corroded themselves in there, and having to drill and weld new studs in on the tracks. No need to reengineer it. If you you really want a secondary safety, use loctite, or drill the seat mount stud past where the nut will sit and pin the stud with a cotter pin, then if the nut loosens it cant rattle all the way out. If you dont like nylocks, you can buy locknuts that are threaded, then squeezed to a slight oval for a locking feature. Then you can use them multiple times, and not worry about them loosening up, and not need loctite on them either.

Multiple places on our mopars where these ovaled nuts are located because of high heat, vibration, and general worry about them loosening up. Trans crossmember thru bolt nuts, engine mount bracket to engine ears mount nuts, the nuts for the large bolts that attach the disc and drum brake spindles to the lower ball joints. None of these are nyloc nuts, or use a lock washer either, however they all are a squeezed ovaled mechanical locking nut. Aviation terminology (jap nut). Dont over think it guys.