Just wondering, if I had a strat that was locked down with five springs and effectively making it a fixed bridge, will a better block like a Callaham have any effect on sustain, etc?
Depending on the block, you WILL change the tone a bit. How exactly depends on what exactly is on there and what you switch it for.
This is one of the reasons I prefer Floyds with 42mm Blocks instead of 32, even in recessed routs where they barely fit (or to be more exact, only fit if you remove the cover ). A bit more sustain and an improved bass :smoker: