Sleeve Asus Dell

Are all heatsinks compatible with all motherboards? Are the mounting holes standard?
I bought a Dell Optiplex 755 barebones ($100 eBay) and an Intel Q9550 CPU ($230 eBay). Now I’m looking at the ASUS V72 92mm Sleeve CPU Cooler($30 Newegg). I’m on a budget, will this work?
I also got:
8GB 240-pin DIMM from ($100 Crucial)
512MB nVidia (owned)
Dell used to use propriatary Mobo’s looking at the specs of the mobo it looks like it should be fine.
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