line lock

I am unsure about the B&M line lock but I have a Hurst roll control and the nut just holds the actuation coil on the valve it is not an adjuster (the nut has super fine threads). As far as the brake lining is concerned organic linings (non-metallic) will hold better then metallic linings when the shoes are cold and metallic linings will have better holding & stopping power than organic linings when they warm up. On my race car I have organic linings on the front and metallic linings on the rear. This way I have the holding power up front when the brakes are cold but the stopping power in back when the brakes warm up. It's like a built in proportioning valve that puts more stopping power to the rear (when my brakes warm up) which is what I want because of the large size of the slicks compared to the small size of my front tires. I do not recommend doing this on a street car though, you should stay with like materials front & back (at least in a drum application). If it is a street car and you deside on metallic linings (which are better linings) just heat them up a bit and then they will hold better than the organics.