Difficulties installing & torquing rear drum - Help!

[psogden]

Hi guys & gals. Read every Ford Barn post I could find on the subject, Dick Flynn tips, etc. before starting to torque the 5/8 – 18 axle nut and found out the conventional wisdom is a final torque of 200- 225 foot pounds. Proceeded very cautiously inching the nut on and carefully measuring every 10 or 15 foot pounds. When I got to 175 the nut failed. The nut, by the way, was purchased from a well known reputable Old Ford V-8 parts vendor. I took it down to my local NAPA parts house to see if I could get a replacement. All they had in stock was a non-castellated variety (not surprisingly). They guy behind the counter felt that my nut was not a Grade 8 quality and, given my experience, I am inclined to agree which makes me wonder about the reliability of the folks that sold me the nut. I purchased a non castellated Grade 8 nut from NAPA and ran it on to the axle to see what would happen. Unfortunately it stopped before it reached the drum. So, I removed it and checked the axle threads which seem to be ok. So, should I run a 5/8 -18 dye over the threads to clean them up—or am I looking an axle replacement? And where do a get a Grade 8 castellated nut? Finally, do I really need to torque to 225 foot pounds? That seems like a lot.