I'm using these same shifters with a Shimano Exage 500LX rear derraileur that's probably not much different at all from your Deore mech. 28-38-48 cranks and 12-32 cassette. I'm running it in friction mode, but that's just my personal preference. It should index fine for an 8 speed drivetrain. It's the lever that determines the number of stops/speeds, not the derrailleur. The reason why it wasn't Dura Ace compatible was that Dura Ace 9 speed systems had a different cable pull than Ultegra and lower systems when those levers were introduced a while back. They're great shifters- mine have scratched easily with use, but never come at all loose or compromised shifting.