Spyke wrote
I actually use very little trem in what i play, i could easily settle for a fixed bridge guitar. But I play with what I have.
Likewise. Anyway a Strat isn't quite a Strat with a fixed bridge. Even if you don't use the trem it adds a certain something to the tone.
I also now realize that the third trem spring is a little overkill now but it holds it's tune a lot better now.
You only had two before?

IME, Strats need three to be stable. Two gives you a kind of Floyd floppiness, which a Strat bridge is not designed for.
How would one pre-stretch the strings?
Simple. Give them all a rough tune. Tune the 6th again and then grab it and pull it up away from the fretboard a couple of inches. Check tuning and you'll find it's flat, so repeat. After 5 or so stretches you'll find it doesn't flatten after stretching - it's more or less settled. Then move on to the other strings. While you may get a little slippage over the next 24 hours, you'll find it's much more stable - probably 99% of the way there.
For the Floyd-equipped guitars, doing this before you lock is essential. Screw the fine tuners out all the way, stretch the strings until they settle and then lock down the nut and you'll find you don't have to loosen the nut until you next change strings.
Also remember to have as few windings as possible on the tuners. Two is perfect - one above where the string comes out of the post hole and one below. The less windings, the less there is to stretch. With locking tuners, where you only get half a turn or so, I can usually put strings on half an hour before a show and go on with complete confidence.
With a Floyd, flip the string around - put the ball up on the
tuner side, stretch the string down, clip to length and lock - this works like a locking tuner so it doesn't take long to stretch in.