I'm drilling a 2 3/8" (1 1/2 bulkhead) in the sides of my overflows. These two holes will be the intake for my AmpMaster 3000 closed loop. My question is where do I get a 2 3/8" hole drill bit? I have smaller ones, but 2 3/8" is kind of big. I searched Home Depots website real quick and came up empty...Would they have them if I went into the store?