So the threaded screws I have for my 1 space effects all fit just fine. The korg, the furman, the bbe all use small hex head bolts and nylon washers to prevent rack rash. Now that my Mesa is getting a 4 space rack, I tried using one of the bolts from the other units, and the head turns down into the bolt hole in the amp. Do you guys use another size bolt head? if so what thread? if not, is it just a larger washer you're using. Lock washer or what? sorry if this sounds like a dumb question. just want the 45 lb Mesa to sit right .