Mustang Style IFS Swap 1968 Dart

Having your front frame rail piled up is a blessing in disguise . You can start fresh with the rail width ,height and placement .
You are not constrained with the retarded upward angle of the front frame rails the make the upper controls arms on the alter-k and Bob's disaster front end abortions fumble through their confused travel . Put the frame rails at 10 degree's up and make a standard A-arm suspension that you can buy anywhere.
Front suspension geometry is covered in many books and there are plenty of excellent tech articles that will explain in detail the fundamentals and standard pivot points in order to reproduce a competent front suspension .

To many people think front suspension is voodoo magic ( similar to the torque converter ) and are afraid to build their own , if you have the resources than do it yourself .

you have some good points....

the limitations of the width of stock frame rails added with the set placement of the stock upper control arm mounting points makes it challenging, to say the least.

if I were building a road race car, I certainly would start from scratch, in fact, I would not be attempting to tuck(narrow) my front wheels in or slam the car as low as possible, it would make more sense to widen out the track width and have a little more ground clearance....but that is not what I think the majority of us are not trying to accomplish. And a throw-down drag car...lets start with a cage, 4-link, ect...

most are just trying to put in a bigger motor, get the stance to look mean......or maybe to enhance room. The point is unless major metal surgery (non bolt-ons) is involved in our beloved Mopars (can you say... devalue) , we are stuck with the mounting /attaching points and frame rail width that they came with. Are they gonna be world beater road racers?...I doubt it, but they never were......but OMG....what great hot rods!