Replacing logic board on Powermac G4 quicksilver

Ok, So i'm replacing a logicboard on my powermac G4 quicksilver, and i have a question about the heatsink being remounted on the processor. Do i need thermal compound, and if so what type? It doesn't appear to have any from the factory, but i could be wrong. (figured i would ask before tampering with it). Anyways, thanks in advance for any insight or suggestions.

There should have been stock paste on the chip, you will need to reapply the paste or the chip will overheat and die.
The best thermal compound is Arctic Cooling MX-2 or MX-3

Instructions on how to apply it, article uses a G4.
Tutorial: How to apply thermal compound

Another Guide,
Installing Computer Thermal Paste - iFixit