what fairly simple mods could i do on a american stock strat? like what would adding 2 (making it 5) more springs in the back for the tremlo do for the sound? adding a pushpull pot? and what ever other mods i can do *one more thing, i have seen some people with a little toggle switch in between the 2 tone pots and some times in other places, what does that do? is it like S1 switching? thanks in advance.