Who is using long wheels studs on their C4?

[Ken]

I'm once again in a quandry here about what to do about installing longer wheel studs to meet the requirements mandated by many race sanctioning bodies, in my case it happens to be the National Hot Rod Association (NHRA).

My problem is finding the correct knurl shoulder diameter. All of the fastener manufacturers (Moroso, ARP, etc.) make studs with different sizes and applications:

• Late Model GM Drum Brakes - 7/16"-20 x 7/8" press-in stud with .480" knurl - .472"-.479" hole

* I just checked that measurement (.472"-.479") and compared it to the metric size which turns out to be 12 millimeters. But why does mine measure in at a little over .500", is it the knurl that is not taken into account? :confused

• Late GM Disc & Early Drum Brakes - 7/16"-20 x 7/8" press-in stud with .560" knurl - .552"-.559" hole
  
• Chrysler front and Ford Disc Brakes (front & rear) - 1/2"-20 x 3" press-in stud with .615" knurl - .606"-.613" hole
  
• Chrysler Rear (with 1/2" stud) - 1/2"-20 x 3" press-in stud with .685" knurl - .676"-.683" hole
  
• Aftermarket Axles - 1/2"-20 x 3" screw-in type fits all aftermarket axles with 1/2"-20 threaded hubs
  
• Frankland Disc Brake Hubs - 1/2"-20 x 3" press-in type features a .563" diameter knurl and quick-start dog end for use in 1/2" Frankland hubs
  
• Oval Track - 5/8"-18 x 3" press-in stud with .672" knurl

My original wheel stud measures in at approximately .503" which is neither the first or the second choice in the above list. :confused

Please don't tell me that I must bore out the holes on my hubs and rotors to install studs that will meet the safety requirements. :cry

_ken

 

[widebody]

Ken,
ARP makes a 2 1/2 long stud just for the f-bodies and the vettes.
It is 12mm, 1.5 pitch, direct press out and press in application.
Part number is 100-7708, knurled diameter is .509. They do exist, I have them in my car!

 

[Ken]

Thank you very, very much Terry!

_ken