Okay,

The metal shackle itself is fine, but the rubber bushings in both the spring and the shackle probably won't be too happy with
the heat of an exhaust pipe (assuming this will be driven enough to get the exhaust hot: bushing damage).

Two ideas I'd consider, or maybe a combination of them:

-A slider instead of a shackle, which is more compact/takes up less real estate, and does not contain
any rubber, eliminating the concern of melting damage by having the tailpipe in close proximity.

-move the tailpipes inboard a small amount, just enough. Maybe 1 and 1/2 to 2 inches.
Not enough to be very noticeable as far as overall visual appearance.
Slightly longer versions of the factory style tip hanger as attached could be fabricated pretty easily to help this along.

This is easily possible especially with the stock gas tank gone, and I'm sure it's been done.

Good luck.