The rear brakes are usually the circuit that is closest to the pushrod. pressure builds up here first before actuating the other circuit.
It's the other way around. 99% of vehicles with a split system have the front brakes on the pushrod end, rear brakes on the other. Many times, the ports are different sizes just so they can't be swapped the wrong way.
89.7% of all statistics are just made up!
Maybe it doesn't make that big of a difference. The CPP MC kits for our trucks are set up with the rear brakes closer to the pushrod. On the corvette style MC, the circuit closest to the pushrod actuates the other circuit after pressure has been built up. There is a mechanical interlock that will actuate the second circuit if the pressure hasn't built up.
Maybe some MCs use a solid link between the 2 circuits making this timing less critical. Combination valves can also provide a slight delay.
I don't have the time or the resources to investigate every MC setup, but the MCs that have been specefically setup by the aftermarket for our stovebolts use the circuit closest to the pushrod for the rear brakes.
