Like I was saying before. You have to understand what the faults are of these suspensions, how they relate to your intended use and how to rectify it. Then you can pick the right components. Keep in mind, the more chances to one part is going to effect something else and maybe not in a good way. You have to find a balance in it all
After that what I discovered is like winning the pony. You have, now what do you do? You’ll need to know how to set it up or you’ll never get the performance you’re looking for! I came to that realization after I had my suspension done. Now what, send it out to the local chain store for a alignment? Good luck with that.
Understand the faults in order to decide what to change/fix for your intended use. Lots of reading and research.
I went through a similar decision process recently and thought I’d put together the options I considered for your review. Of course, the first thing you must decide is what are you’re going to do with the car. Talk to Opentracker and Street or Track first. Do research and watch the SoT, CJ and Global West videos. Understand that you probably won’t find a “best,” just lots of good options.
Level 1. For the occasional driver to the Dairy Queen all that is necessary is a refresh of the suspension parts. Most cars this age will need all of the rubber replaced – bushings, boots – and ball joints and tie rods. You might also consider replacing the UCA and LCA as they have aged.
Level 2. I’ll call this “Period Correct Update.” You can install all the upgrade options that were available at the time. The Shelby drop, as mentioned, is an absolute. Then roller spring perches (ok, they weren’t available, but the original Falcons had a bronze bushing so it’s close), 1” sway bar, stiffer/lowering springs and shocks (front and rear), export brace (the good one), and roller idler arm. All of these options are available at multiple good vendors.
Level 3. I’ll call this “Looks Period Correct.” Replace the UCA and LCA with reinforced examples of the original which include spherical bearings, Del-a-lum bushings, or similar rubber replacement. Opentracker, Street or Track and Global West offer good products, among others.
Level 4. Call this “Looks Period Correct – Sort Of.” Step up to tubular control arms and adjustable strut rods. Plus sub-frame connectors. Street or Track, Opentracker, Global West, to name a few. And consider Zray’s cross-member.
Level 5. Not sure what name to give this level. Here is where you go with coil-over front suspension. This is probably the most bang, but for an increased buck and loss of “originality.”
Level 6. Forget all the above, and put in an entire new suspension front and rear.
Of course, you can “mix and match.” Many put adjustable strut rods, sub-frame connectors and Zray’s cross-member with original style arms.
For the record, I wanted a road-trip setup for long vacation drives. I went Global West tubular suspension for the caster gain without excessive alignment adjustment; plus I added other good stuff. Remember, you can always step-up. Be sure to replace what needs replacement even if with stock parts as they are relatively inexpensive and will give you the most improvement for the least cash.