Re: PUPs in Standard Mexican Strats?
If you don't want to spend the cash on a new bridge pickup right away, just wire the bottom tone knob so that it only works on the bridge pickup. This will give you master volume, neck tone and bridge tone, letting you control the treble output of your bridge pickup and giving you brighter, quackier sounds in pos. 2&4.
I do it to all strats with passive pickups.