by staggerwing » 09 Wed Nov, 2011 11:04 am
Update: Drilled the existing rear drums to except a 5-hole Chevy pattern. The bolt we put in the hole as a plug (cause you have to plug one existing hole) was welded on the inside and ground off flat on the side facing the wheel. When it cooled, the plug was too hard to drill through - dangit. A standard drillbit wouldn't work, a carbide drill bit wouldn't work, and an end mill just bounced on the plug as well. Put some studs in the wheels and went to the car show in Wallis with one lug missing. Bryan didn't notice so I guess it was okay. Ordered some new drums with Chevy/Ford pattern from SoCal (ouch) and things are better. Oh yeah, before drilling the old drums, we chucked them up in a lathe to lay out the pattern and checked them for trueness. One was out 0.020" and the other was out 0.022". The new drums were not checked so I can't say if the cause of the vibration was the old drums or the wheel adapters. The vibration is gone though, and I'm happy about that. The fronts are next; problem with that is nobody sells blanks or drilled front drums. At least I haven't found anyone.