Based on some advice from other racers, I am installing some front calipers on the rear of the race car.

I have stock front calipers, stock rears, and a 19mm MC, and still have the stock rear prop valve.

I have a few sets of late front calipers that I disassembled to rebuild for this change.
One of the calipers had the pins for the knock back mechanism broken out by some previous owner.

I understand that the newer A-calipers do not have this mechanism from the factory.

How many others here have done the front caliper installation on the rear?
Did you keep the rear prop valve, or go for an aftermarket like the tiltons?
Has anyone heard of breaking out the knock back pin?
If so, what advantage is this supposed to provide?

Should I use calipers with the knock back system intact, or should I break the pins out of another caliper so I have a matched set?

I plan on running KFP Gold pads on the front and Porterfield AP31T R4-S pads on the rear for some front bias.

Any more tips or tricks ?

I did this years ago but do not remember anything about a pin. I used a "tee" instead of the prop valve. I can't ever recall what brakes I had up front at that time, probably 911 S or A.

Yep thats how my car is right now. Very common thing to do on the cheap.

Which part? Are the knock back pins missing?
If so what is the difference between having the pins and not having them?