I have a stock '75 280Z which is showing excessive outer edge tire wear on both back tires. I have been informed that I have too much positive camber and need some negative. The problem is, without some suspension modification, this is not correctable with the current stock control arms. I have been presented two possible choices to correct this problem. One choice is, purchase a custom made adjustable control arm, which is very expensive. Second choice is, purchase a much less costly camber adjustment kit from MSA catalog (pg 65). Does anyone have info about this problem/subject that could help me make the right choice at the least cost to fix it right. Thanks.