Well, here is the issue: Tony also said to replace the amp in the same post (no offense Tony).
Lest just speculate for now, since we dont have any hard data. Lets say that the Clarion is a 450 Watt 4 chnl amp, that 112W's p/chnl. I'll bet this is at 2ohm's. Just to be conservative, lets guesstimate that the 4ohm output p/chnl is 85%, that puts us at 95W's p/chnl @ 4ohm, to each speaker pod that would like to have 150. As tony has experienced, it's no advisable to bridge the KTM6's as they are around 3ohm's.
I hate to tell you that you need a new amp without knowing exactly what model it is, what the specs are and whether is will work or not. My gut says, if your positive it's the Clarion 4 chnl, then I'm 99% sure it will not cut it for the KTM6's and you will not be too pleased.........as with any under powered tower speaker set up.