I am doing a complete brake job as the car has sat for years and a new motor and trans are going in. My question is this; one brake drum had three weights on it the three others have none. Were the drums balanced individually or is this balance for the rear axle. Can I put back on any where or is it specific to it's origanal location? Obviously I am asking because I don't remember witch side it came off of. Doh. Here is a pic of the drums in question. the arrow points to the weights.
Also will sand blasting warp the drums. I have cleaned the scale off with a wire wheel and want to blast them for the best paint adhesion.
Thanx all for your help.

just a balance weight for the drum itself,some have it some don't and it'll go on either side just fine.

Whew Thanx alot That one must of been off the jig when it was welded. OK now back to the garage.