SBP DISC to LBP DISC SWAP- 72 Swinger

StephenShaw said

Hey guys I need to do drum to disc on a 72 Valiant. I used the list above and found a 85 Diplomat and got the set up last weekend. Now I see on Mopar Action On-Line there is a thread called "Disc-O-Tech" that says not to use the taller knuckles found on 73 and up B/F/J/M/R cars and they should measure 4-9/16" from the back spindle hole to the underside of the top ball joint connection. If taller than this you will change the camber and bump steer effects. Not sure what bump steer is. The Diplos are about 1/4" taller. What will using these taller knuckles do to the car steering?

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The Mopar Action article does a HUGE disservice to this swap. Basically, they throw a ton of BS out there without even investigating the actual changes.

Mopar Muscle actually did the swap and analyzed the geometry, and found that while there is a little bit more toe change because of the spindles, they also improve the camber gain throughout the suspension travel. The toe change (the dreaded bump steer) is almost insignificant. But, the camber gain is very beneficial, even in small amounts.

The Mopar Muscle article is here

Basically, for a street car, you probably won't notice any difference between the '73 up A body spindles and F/M/J stuff. Except of course in your wallet, because you can get the F/M/J spindles from most wrecking yards still. I paid $60 at PickNPull for a set of spindles with caliper brackets off a Diplomat.