Adjustable strut rods post-install thoughts

This is my idea of a half-a$$ fix but maybe try unbolting the support rods that hold those corners of the fenders and see if pulling or pushing the fender would make it clear? Then fab up some longer or shorter rods to hold the fender in the 'proper' spot. I'd still be leary of going over bumps in a turn though.

That's what I did on my Duster to clear my 275's. Granted, not a Barracuda. But adjusting the lower fender to bumper brace makes a difference for tire clearance on that lower front corner of the fender. I did exactly what you described. First I maxed out the brace, then I unbolted it altogether and pulled the fender corner out, and then I decided how long the brace should be and made it longer.

Here's the modified brace (I had a few extras)
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And here it is on the car. I cut the corner back as indicated as well. 275's up front are big.
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