Disk brake parts swap
They physically fit, but can screw up the geometry. The RIGHT knuckles/spindles are 73-4 E body and 73-6 disc brake A body.
They don’t “screw up” the geometry. This is BS that Ehrenberger threw into his “disco-tech” article a million years ago with no numbers or evidence to back it up.
Using the FMJ or B body spindles primarily does two things, it
slightly increases bump steer, but also improves camber gain. More significantly than it increases bump steer.
You can actually see all that plotted out in this article
Swapping Disc-Brake Spindles - Mopar Muscle Magazine
Because I run wide front tires (275/35/18’s) I actually prefer to use the FMJ spindles. The camber gain with wider tires is more useful than the small change in bump steer is detrimental.
Like everything in suspension, there are trade offs and how you use the car is important. But the FMJ and B/R body spindles don’t “screw up” the geometry. The change they do make is small, to the point that most probably wouldn’t even notice.
And if anyone agrees with Ehrenberger, I’ve got a set of 73+ A-body disk spindles I’d happily trade for a set of FMJ’s straight across.
