Any idea how to get fittings out of aluminum intake?

I forgot to bring it with me today to use the torch. I've been soaking it with PB Blaster all weekend. I've used my impact tightening and loosening off and on all Sunday. I tried cheater bars to lengthen the wrench. Slippage is not a problem, so I don't see the advantage of a pipe wrench, other than the bigger bite. Tonight I am going to try propane on the nipple. Those sob's are coming out!