The only thing I modded on my leadtek Geforce 3 Ti500 was to change the heat-transfer paste below the enormous heatsink which covered bothe the GPU and the memory-chips.

Here is my Leadtek Geforce 3 Ti500. Removing the heatsink is fairly easy, it is held in place by 2 plastic clamps which can be removed and used again by carefully squeezing them with a pair of pliers on the back of the card.

After having scraped of most of the heat-transfer paste with a razor-blade, I cleaned the GPU and the memory-chips with alcohol. The paste was then replaced by Arctic Silver 2, carefully applying an amount that would not go over the edge of the memory-chips, as this would short-circuit them.
Then I reinstalled the heatsink and pressed it firmly in place, moving it slightly to ensure good contact, before fastening it with the plastic clamps again.

Next: The Watercooler