Whether a machinist does it locally, or something is worked out with Moser to supply the axles with the flange holes made to order (for the larger studs)--the stock replacement axles will not work without modification.
(quoted from catalog page linked)
Must Drill To 1/2” & Ream Hubs To 9/16” With (.562”) Reamer
Bill, the 100 LB torq is the correct amount for a 220,000 psi stud. This is using ARP moly and that spec came directly from them.
Still agree the 14mm is a better way to go. But to save the cost 5/8 would be what most would do as it's nothing special to deal with.
Jeff, the factory doesn't use lube on wheel studs for a reason. My take on ARP's reply (to my inquiry) is that they concur--whether the actual torque value in this case was correct or not wasn't what I was questioning--the GM M12x1.5 wheel stud torque value has been 100 lb/ft "forever".
Given the information from GM & ARP, I'm not sure what is the rationale to continue using moly lube on the wheel fasteners.
At this point I would want to measure the length of a new ARP stud (not sure of the PN you're using) and one installed on your car to see if they're the same length (or not)....ie. IS there a possibility that the studs ARE stretched--and, if so, why?
Not sure what the comment "save the cost" implies--no matter what size larger wheel stud is used, the flange holes will have to be enlarged, and drilling to 1/2" then reaming to 0.562" is a standard machine shop operation, whether the stud is 14mm or if other sizing increases are needed for 9/16" or 5/8"--knurl dimensions are not standardized.
An example of that which I've seen often with B-body is that many replacement front rotors (from both domestic and offshore sources) do not always use the same stud as the OE/production rotors used. When a stud breaks or the need to install longer studs comes around, the available options get more complicated, since it's not simply a matter of using the correct part listed for production rotors, and/or the appropriate ARP stud pack (100-7708, for example) or other known "direct-fit" longer stud options (Dorman 610-323, GM 22551491) that have been mentioned here on Forum in numerous other threads.
My point is that the head on the Sway-A-Way 14mm studs is not typically going to cause any clearance issues on the back side of the axle shaft flange in an otherwise 100% stock installation. I'm not sure the other larger studs mentioned would afford that same clearance while maintaining a functional park brake system, since some have larger OD and/or thicker heads that very easily could interfere with the park brake shoe(s).
My additional thoughts on this:
1. The ARP catalog wheel stud page shows knurl diameters that range significantly, depending on application. The stud kits listed were created for direct fit to replace OE studs, in most cases. A non-standard parts mix--which up-sizing to a larger stud will be typical--calls for re-sizing the holes in some way.
2. While I'm not "knocking" ARP for any lack of information in this area, Sway-A-Way at least has provided a specific recommended process for accomplishing this, whether it's REALLY important for the holes to be reamed the additional 0.062, or if the same desired interference fit could be achieved by use of a fractional-size drill that is close to but smaller than 0.562" is not for me to say--a well-equipped machine shop would typically have the proper tools to do this, but I do know that individual drill bits in "off" sizes get expensive, especially as size goes up.
3. For a specialized application, such as a 4500# "streetable" vehicle capable of running sub-9 second times in the 1/4 at 150+, having ANY issues with drive-axle wheel studs is to be avoided, and finding studs bent suggests that something is not as it should be--whether fastener size, or a torque load issue, or something else installation-related. Hearing of a shearing problem in the past, no one wants to see a car have that happen, whether at the starting line or somewhere down-track.
4. In vehicles that are not serviced on a frequent basis, and used in harsh environments on a year-round basis, I could understand using a little bit of lube of some sort, especially older vehicles. For a car that is constantly being massaged, wheels-on, wheels-off, and not typically driven in inclement weather, lube on the wheel fasteners is not needed--as there is no chance for corrosion to become a problem that could affect proper torque readings or attack and weaken the parts. Many wheel studs and nuts now in OE/production use have zinc or other coatings that suppress corrosion and provide some degree of lubricity without adding anything else.