Originally Posted by chevmal
Does anybody know if 1982 Firebird front disk brakes will fit on the front of a 1969 GTO? Thanks AL
Again, no. Most importantly, the 82-up F-body uses a strut-type front suspension. The A-body uses upper and lower control arms.
The 64-72 A-body, 67-69 F-body, and 68-84 X-body GMs all used the same spindle design and the same ball joints. Nothing else is a direct interchange. Even if you find a spindle that you can physically bolt up to the ball joints, the biggest problem is that GM changed ball joint designs and starting in the mid-70s the taper on the ball studs is different. Since the ball stud is designed for a uniform loading along the entire taper of the stud, the taper mismatch will cause excessive loads on the stud and can lead to breakage. Also, the later cars have different locations for the steering arms, which results in bump steer and handling problems.
One popular swap on the A-body cars is to use the 70-81 F-body or 77-90 B-body spindles. The B-body spindles can even be had with 12" disc brakes. The problems are 1) you still need different ball joints due to the taper difference, 2) the taller spindles require custom upper control arms to enable the alignment to be set properly and 3) you still have some bump steer problems.
The only thing a third gen (82-up) F-body front suspension has in common with the 64-72 A-body cars is the 4.75" wheel bolt circle.