With the 1" drop it does not require bump steer correction. With the 1.5" drop it will.
You'll also want to use the Global West LOC-2 Excentric lock out kit.
The specifications that have worked best with the power steering on my 1967 Sheby are:
Caster Passenger side: 3 1/2 degrees positive.
Caster Driver side: 3.0 degrees positive
Camber: Driver and Passenger 1/2 degree negative.
Toe in 3/ 32 total.
This is for power steering and I haven't had abnormal tire wear with these settings.
All I can do is share my experieces. They may vary from yours. In my case, the 1" drop resulted in what I would describe as severe bump steer.
I do remember that there are two pattern configurations for the 1" drop.
One is where the bolt holes are plumb to each other. The other where the bolt holes wind up parallel but something like 1/4" or 3/8" behind the plumb line.
I think the plumb pattern is what was used by Shelby on the '65s. The second method is what was being recommended for the later cars coming out of Kar Kraft and what I used.
I'm not sure if that would account for the differences in bump steer issues or not. It's my understanding that is more an issue with the steering arm location on the spindles.
The simple solution being to raise the height of the mounting of the tie rod end about 5/8".
I have heard from others that there is a difference in Castor settings between '67s and '68s. I can't verify that one way or the other.
In my case, the COMBINATIONS of front suspension modifications limit my castor to a maximum of about 2-1/2 degrees befor the tire hits the bottom front of the fender opening.
My tire, wheel, wheel offsets with my configuration likely are different then others and logically could explain the limitations my combination has.
I will say that castor really is the largest factor in giving the car straight line stability combined with ease of steering through turns .
To answer an unasked question, yes the car has participated in high speed events, is a street car and not a race car and has pinned the speedometer with no steering where you want it to go issues. Again, these are done with my combinations. Yours may and probably will vary?
I don't do this for a living. I speak from 48 years of specific experience with my 68 GT350. Most is trial and error, with lots of error and more trials.
I just share to save others from going down the same route of mistakes and I'm not a lawyer here to debate the meaning of what "is" is, or debate what is necessary, or what is severe.
It's a free country and everyone should have the right (although that seems to be a legal term) or more correctly the opportunity, to venture out on their own and make their own mistakes, discoveries and accomplishments. It's all part of the experience I suppose?
Mine has been an enjoyable and busy 40 some odd years of "experiences". I hope yours will be too? Best...