I want to puchase a new exhaust system for my F-150-- new high-flow cat., muffler, and dual tips. Right now I have stock cats., and a Flowmaster muffler with custom steel tubing (one in, two out) with dual chrome tips. I know that mandrel bent tubing is the best way to go, however I don't feel it's necessary to spend an arm and a leg for a few extra horses. Should I save my money and just go with the cheap aluminuzed tubing that's ribbed where there are bends, or should I pay more and stay with the steel custom bent piping. Right now, I have 2.25" piping, and I will be upgrading to 2.5" piping out of the muffler. So my question is-- how much of a difference does the custom bent piping or even the mandrel bent piping make over the crinkle bent piping. And is it worth the extra dough? Thanks in advance!!!