Had a moment of clarity.
Was overthinking the head pipes. My goal was not to have to lift the engine to install head pipes. Decided to remove the rear A arm mount and see how that went. Still really tight. Mocked (hacked) up a head pipe just to see if I will follow through with the 2.5" which is pretty tight but I could always ding a bit where needed.
So the big question: Run 2.5" and ding (dent) as needed.
Or..........................Run 2.25 and no dings(remains to be seen)
Input welcome.
HP is not a big goal, but hey Hot Rodders gotta Hot Rod!