Brake rebuild...ummm

[dweymer]

ok, so my brakes were dragging, and I decided to rebuild the calipers, and replace soft lines. This is on my 74. I order supplies and then remove all the calipers. I then realize something very strange, my calipers have different pistons in them from side to side. Both pistons in each caliper are the same, but passenger side is different from drivers side. This is a pic of my rear pistons one from the drivers side(with nipple, for lack of a better term) one from passenger side without. Both are same dia. but will require different dust boots. The one on Pass side looks to be correct, based on the seals supplied in rebuild kit. What is the right one?
Same issue with fronts, driver side has nipple, pass doesn't.

Any help...

Have been doing some research and it seems these(driver side) pistons/calipers have disk balancing/venting. Can anyone confrim this, and good or bad to have.

[dweymer]

morning bump..