As far as blocking a Strat's floating bridge, if you don't understand it, you could always ask Eric Clapton why he does it. Now as far as setting up a Strat to stay in tune all night, you set the bridge at 1/4 inch from the body and put on genuine Fender locking tuners. I play heavy and only go out of tune at all, very rarely. For the original post, first tighten the two screws on the claw. That alone might solve it. If not, take the two outside springs and run them to the holes next to the center spring on the bridge block; a very common way to add more tension. If that fails, add two more springs. But first, tighten those two screws on the claw!!! Locking tuners are the most important upgrade to any Stratocaster. I cannot overemphasize that enough. I am a lifetime Stratocaster player and owner. Stratocasters do NOT go out of tune any more than any other guitar when set up properly.