You didn't say what design STB you had. Each design mounts differently. For example, some STBs attach to the firewall through the cowl area with bolts, washers and nuts - you pre-drill the holes; some attach through the firewall pinch weld with bolts (I think the stock 96-97 STB was of this design). At the strut end, some attach using the strut mount holes and bolts, while others need separate holes drilled and separate bolts. Given the forces at work, don't think sheet metal screws will cut it.