@Mo 3 The thread is 5/8-20 which I was unable to find anywhere (and I'm pretty steeped in the world of nuts and bolts). That's why I had to custom machine a set, DM me if interested, also DM me if you do find a 5/8-20 threaded bolt at a reasonable price because that would be much more helpful to the community rather than having one guy custom make them!

@TimInNova How have they been holding up? I made and installed my original set to on an engine I was rebuilding for when my current one lets go, which I thought would be much sooner but she keeps chugging along at 195k! I've made probably a dozen or so sets at this point and haven't heard any feedback so I assume they are doing the job.

 

They've been in the heads for 2+ years and maybe 15K miles without any issues. I used some liquid gasket on the threads before screwing them in. You made a great product for our community and I am very grateful!