definitely not outside if you plan to use the grill.
problems fitting inside:
1) you would definitely need low-low profile ram. samsung green is the only low-low profile ram i know of. all other ram limits you to less than 45mm depth. (probably 40mm)
2) may not clear waterblock even if you use 90* fittings.
3) may not clear cpu 8-pin
4) may not clear uppermost vrm(?) heatsink.
the 500r wasnt made for serious water cooling. it was made for the all-in-one, closed loop kits. basically only the slim 240 and 280 radiators fit. the best of those as of right now is the ex280.