Hmm found my answer from Alex.
"Unfortunately, the technical improvements in the new G4 required the use of a new heatsink, LED clusters, lenses, driver board and power supply. Because of these changes the shared parts between the G4 and previous models are minimal. With this in mind, attempting an upgrade from a previous model Radion would equate to the same cost as purchasing a new G4. That said, if you're having good results with your current model Radion, upgrading is not recommended. "
Please close thread.