I'm beginning to build my first bass from el-scratcho and have a few simple neck questions.... 1: Do you all suggest using dual truss rods on a 4-string? 2: If using the 'hotrod' rods that stewmac sells, do i need to put a filler strip of wood in-between the rod and the fingerboard? 3: if using a simple ABM bridge, it's not necessary to create a neck angle, right? 4: what size frets do you all normally use? thx in advance..