Grade 8 sell a locking fastener for header bolts. They consist of a groved header bolt, locking retainer and c clip. The one from Jegs are probably the same. When I was at the SEMA I talked to one of the reps at their booth, as the locking retainer always had to be ground down to make it fit on header, and that didn't always work. They now have another piece that replaces the locking ring over their header bolt. Its a flag nut and it comes in two sizes. It has solved my problem using the smaller version. I'm not sure that its shown on their website yet, www.stage8.com, but the guy I talked to is Glenn Thompson at 415-485-5340. Give them a call and they might be able to help you.