With a strat there is that reverb chamber thing that happens with the springs, which may be why Clapton preferred a blocked trem to hardtail.
I have a Kramer Baretta that was my first good guitar at 15 years old. I later found a piece of hardened steel, it was a gear from a transmission, that fit perfectly to block the Floyd Rose. Best block ever, seemed to transfer all of the energy into the body.
I've also tried having a machinist cut aluminum perfectly to block a strat trem, as well as wood blocks, didn't notice any improvement with those ones as I had hoped. Now I just deck a strat trem with 5 springs. I have also tried letting a strat trem float as some recommend for best tone. I can't deal with floating trems, I play too many doublestop bends and break too many strings and didn't notice any tonal improvement, either.
I'd have to recommend you find piece of hardened steel that fits just right, though that would be a fishing expedition.