I guess that all depends on your tubing bender. If you have one of those benders that uses a bottle jack and came w/ various dies as a whole unit, then you'll probably experience kinking as the mandrel will not be a tight enough tolerance wise to hold the bend tightly enough. The whole "What happens when you hit a wall at 100 MPH?" is a dumb argument anyway, as I'm pretty sure the stock stuff would wad up like chewing gum as well. I still scratch my head and wonder what you think you're gaining by doing this, citing "extra clearance benefits", especially since you intend to use a smallish LS engine under the hood in the first place. We all know there is enough room in the stock configuration to fit a 460 oinker in there, w/ room for 3 little pigs too.
I guess my new question is how are you intending to mock up mount points for the front sheet metal w/o stock reference points?