What are you looking for Andy? Tone? Sustain? As far as I know, the SEs have a steel block (with most of the US models being brass) but the trem is also inferior in other ways, quality of casting, components and materials.
If I was looking to modify the trem on a SE, I'd prob change it out with a US one (which I have done) or a Mannmade 1-piece.
Interested to hear if anyone has changed the block out for say a KGC one though