The amp experts should be on this pretty quik, but here's my take: You'll be just fine. The thing that damages amps is if you go below four OHMS (unless the amp is rated for two, which most are not). With that head you could use two 8 OHM cabs for a total of 4 OHMS that the amp would be seeing. With just one 8 OHM bottom, the amp will be putting out somewhat less than full wattage, but the effect on actual volume will be minimal, especially with 4 10's. Hope this helps--good luck!
