Can anyone see a problem with using Al feeders instead of copper. I've got a 600 amp three phase service and the owner would like me to investigate that option for cost savings.I'd be replacing 4#250's and a ground for a sub pnl feed, and replaceing the main feeder (2 sets of 4-#350and gnd). All branch ckts would remain Cu. POCO is coming in with one set #500. Other than the obvious proper torquing at terminations is it still necessary to penatrox the terminations? Thanks