I distinctly remember measuring the piston diameter with a caliper and from what I recall, the SSBC caliper pistons were in fact smaller than the factory iron ones. It wasn't a lot but it was something. I guess I could be wrong, this was all 10-11 years ago and I don't have notes to refer to but I'm pretty certain of it.
In my case, the 7/8" bore master cylinder should have created more than enough hydraulic pressure to make the brakes work but for whatever reason, it didn't. I actually changed to the 7/8" from the 15/16" one I had on there originally and there was no change in performance or pedal feel. I was surprised, I was sure the smaller bore master would have done the trick. Rear drums were all new, were adjusted properly and had 7/8" rear wheel cylinders. The car should have stopped on a dime and given change by merely thinking about applying the brakes. Not so much.
The pads are what come with the calipers. You'd think (or at least hope) SSBC would have enough insight into the dynamics of their own system to choose the correct compound for sufficient all-around performance. Again, I bedded the pads in correctly. I learned how to do it at Chrysler dealer tech training school and had done it countless times beforehand and never had a come back from glazed rotors. I wasn't road racing the car so it's not like I was pushing the parts to the limit. The system just did not work well, period.
I even researched pedal ratios to make sure what I had was right vs. OE front drums and all that but none of it mattered. In the end, it was not worth my time and effort to figure out why they didn't perform well so I gave up on them and moved on.
