How to set up a trem
At this point there should be no gap. If there is, tighten the claw up further or add another spring. If you don’t want to pull up on your trem, you may leave it like that. You can also slowly unscrew both claw screws until the bridge is just starting to lift to get a looser-feeling trem with no pull up. Remember to re-tune the strings each time you adjust the claw screws.
If you want a floating trem with some pull up available, unscrew the claw screws a few turns at a time, keeping it square to the body rout, then return the strings to pitch. Work slowly, re-tuning after each adjustment, until you achieve a body to bridge gap of about 1/8" with the strings tuned to concert pitch (see pic below). If you have ultra-light strings and you can’t get the bridge to lift, try removing one spring.
The flaw with this method is that some strings naturally exert more pull on the bridge than others. This is particularly apparent with hybrid sets like skinny top/heavy bottoms. You can get around this by angling the claw to balance out the spring/string tension across all six strings
With Stratocaster trems, you can also fine-tune the response to achieve accurate pitch shifts. For instance, top guitarist Carl Verhayen sets up his trems so that the G string pulls up a minor third, the B string goes up a full tone, and the E string pulls up a semitone. You can try this yourself; just remember that if your trem won’t pull up far enough, you’ll need to slacken the spring claw on the treble side – and vice versa if it pulls up too much.
6. Critical But Stable - Tremolo Workshop