Geforce 4 ti 4600 vmod

[Twisted-net]

I've been folowing the forums for a while now but I have a question.

I want to vmod my chaintech geforce 4 ti 4600 (pic included)
This card is getting rather old so a vmod can give a nice boost.

current overclock : 325/705 Mhz
The gpu is watercooled so heat is not a real problem

Af far as I know the Gpu vcore is 1.66V
I would like to set it to 1.85V (get some more mhz out of it)

I included a picture of the back so can someone say what resitor i need to solder over what pins (solder skills are ok )
I prefer a fixed resitor but a pot is possible to.

edit: can someone also point me the spot where i measure the volts over the core

Picture