Magnum Valve Cover Risers

I was thinking about doing this. I have magnum eddys and although I have not installed them, I have Jomar stud girdles for the rocker studs. The nuts do not clear with the covers I have. You might consider waterjetting the risers. My brother and I have a small manufacturing facility and about 30% of our machined parts are waterjet. You can get as close as .003" on tolerances. Of course if you wanted to oring, you would have to do a second op with the CNC.