Darn.... why didn't someone call me? I should have thought of that.
Thanks for the great ideas.
I notice the spun aluminum tanks offered by Speedway are not recommended for street use. Too thin or non-compliant. Though, I don't know what regs covering (pun?) gas tanks. I'm thinking none since you see so many jacked up trucks around here with their tanks hanging there waiting to get pierced in a rear-end accident.
Maybe someday I'll confess what I was planning for a gas tank. Mine will be (note; future tense) sitting out in the open on the rear crossmember. That makes me a little nervous as I think of it as a target.
Thanks again gents, for food for thought.