Hardware Upgrade 1850R ( CPU / VRM )

[nopf]

I got a Proliant 1850R with 2x PII-450, 2x 18,2G and 512MB RAM. I think the BX-mainboard is able to use faster CPU´s. But there is no information about the VRM´s. Actually there are 2V types in and the limit is up to 600MHz Katmai-PIII processors. Newer ones ( Coppermines ) only use 1.65V and have lower power consumption. I hope there is a way to use 2x PIII-800/256/100 Coppermine by modifying the VRM´s.
Has anyone an idea how to get this or a schematic to manipulate the Vcore?
I want to have this nice device for VOIP-PBX use and little more power......
Thx lot for help.
norbert