Hooker Competition Headers

Pull the studs, and RUN a TAP in the holes to clean up the threads. I used some sealer on the bolt threads. Pick your brand. Permatex or whatever.
I have the ceramic Hooker Super Comp headers on my 340. I personally would NOT remove the flange material. You will need a 7/16" open end wrench for this chore on the inboard bolts of the first and last cylinders. I also have the stage 8 fasteners. There is a technique of starting those two bolts, maybe a couple threads in then populate the other bolt holes. I ground the lock flange on some of the Stage 8 bolts for a better fit. I will get pics soon.