I bet we moved in 1.5 to 2" at least. You can see the before picture here and also 63GT pic in post 10. We cut along the crease just below the crescent bracket and also some vertical cuts below to allow both pieces to push in - see previous pics. Then rewelded. You can see the bracket in the 'after' pictures (post 6) is now more vertical than before.
So now, i just measured about 1" clearance from new distributer head to the firewall just below the crescent bracket (probably had 1.5" clearance with the summit distributer.
I like the shortened distributer idea. If i had to do again i would look at that. But firewall mod not so bad.
View attachment 1715429992