[51504bat]

Seems like we are starting to get wrapped around the axle here with this thread (no pun intended). The bottom line is that there are specifications and limits pertaining to maximum allowable limits for brake drum over sizes. While I'm no expert here is some info regarding brakes which may or may not pertain to your situation.



The Federal Motor Carrier Safety Administration specifies requirements for trucks:
405 Federal Motor Carrier Safety Administration
§ 393.47 Brake actuators, slack adjust-ers, linings/pads and drums/rotors.
(g) Drums and rotors. The thickness of the drums or rotors shall not be less than the limits established by the brake drum or rotor manufacturer.



California (as I'm sure other states as well) has requirements pertaining to vehicle brakes as well:



CALIFORNIA CODE OF REGULATIONS (CCR) SECTIONS 3300 THROUGH 3320]


BUREAU OF AUTOMOTIVE REPAIR BRAKE ADJUSTERS’ HANDBOOK practicable with respect to the wheels on opposite sides of the vehicle.” The adjuster should not certify a vehicle if (1)any drum or rotor exceeds the vehicle or parts manufacturer's service limits, (2)the thickness of the brake lining (friction material) is found to be less than that specified by the manufacturer's service limits, (3) the vehicle fails to stop within the required distance, (4) the parking brake system is found to be inadequate or in operative, or (5) any other condition is found that would make the service braking system unsafe.


The key here is the manufacturer's specifications or limits. Seems clear to me, if your brake drums exceed manufacturer's you are pushing your luck and endangering others.