Fenderwell header clearances.

Ok guys, so I've got hooker 5215hkr fenderwell headers in my 67 cuda that's got a 440.
The headers went in fine, with some slight mods to clear a couple of spots.
I've had to set the ride height way up so the front tires just clear when turning right.
What is the minimum distance I can have between the upper control arm and the droop stop?
I've got as much castor as I can get.
I've got 165r15 tires on the front.