Front tire help 70 Duster

dvw said

Shortening the shaft adds positive caster. The only reason they would be too short is front wheel lip clearance. I understand geometry. This question was posted because the only issue that appearedthat would cause the problem were that the strut rods were too long. I mistakenly assumed that all A body strut rods were the same. Didn't want to go chopping something up if I missed the real issue. Built plenty of racecar suspensions from scratch. Probably performed 5000+ alignments In my career.
Doug

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The front lip clearance isn’t the most important issue. If the strut rods are too short and pull the LCA past perpendicular to the frame you will cause binding within the range of suspension travel. As a drag car that could mean a slower response from the suspension on hard acceleration, so, the opposite of what you want.

I’ve run adjustable strut rods on all of my Mopars, and the change in length to take the LCA from no binding at all to binding at the ends of the range of travel isn’t very much at all. With the tuning process to get the ideal length you basically end up in a window that’s only like a 1/4” wide at the most. The strut rods aren’t there to add caster, they’re only to keep the LCA located properly when it’s under braking or acceleration loads. And if you pull or push the LCA too much with them, the LCA will bind up as it cycles up and down.

Maybe in your case the front tires are tall enough that the fender clearance will be an issue before LCA binding from too short a strut rod is, but the LCA placement is more important.