Just thought i would post this up as a bit of random info, but info all the same.
Weight of 60mm German Steel Charger Pulley = 450g
Weight of 65mm PSD Phase 1 Charger Pulley = 240g
I won't profess to know exactly what this means, but i hope the information might be useful to somebody.
I do plan on updating the post with the main and alternator pulley weights.