Does anyone know the drill bit size to enlarge the shock mount when installing koni yellows? I've looked but every thread i've seen says " drill it out" but nothing specific. i just want to make sure i have all the right tools for the install before i begin.

FYI i'm doing H&R springs and koni shocks, front on top perch and rear on middle perch. Thanks! in advance. i'll take pictures of the process during.

 

I can't remember the size but I just had them drilled a few months ago when I did mine. I used calipers to figure out the drill size. All I can say is that I found it very difficult without a soft jaw vice or drill press. You probably noticed the shock mount holes are not round but have 2 flat sides. It was really hard to drill them because the bit wants to catch immediately on the flat sides and if you can't clamp it down and keep it from twisting it's really hard. The bit also wobbles if you don't have a drill press. I paid a machine shop $20 to drill 3 of them for me. The one I did came out slightly off center and the rubber got a little chewed up on the sides where I had it in the vice. I hope you have better luck that I did. I'm a big supporter of DIY but if you have the time, get it done for you.

I'm pretty sure I used the "stock" spring perches. I have the eibach pro-kit springs, maybe you need to do something different with the H&Rs. Just get it right the first time, it's a bear to change.

 

thanks adam, I appreciate your input. i'll figure something out or maybe buy a drill press for 50 bucks at harbor freight.

 

If you do get a drill press just make sure you have a reliable method to clamp them down. Besides having the right drill, holding it steady is the only other issue I ran into. I would recommend trying to press and hold it on the drill press table, not holding it by the rim of the piece. It's going to want to twist and the rubber on the sides will just rip. Good luck!