3/4 Ton Master Cylinder Question

[NorCalC20LWB]

Been searching for an answer to this, and it seems like I'm getting mixed results, appreciate some input to what I think is a simple question:

In the process of putting a Wilwood adjustable prop valve on my 72 C20. Question is which master cylinder reservoir is for front brakes and which for the back? Setup is stock disk/drum, rear reservoir appears to be larger than front. I haven't traced the lines yet, but coming out of the prop valve one line is 1/4" and one is 3/16" ( I think). IIRC, the 3/4 ton m/c's are reversed from the 1/2 tons?
Thanks in advance for any input, don't want to make any mistakes with brakes!
Brian

[jocko]

front mc res is for rear drum; rear mc res is for front disk (it's the opposite on a 1/2 ton).
Edit - here's a few pics that may help, the second pic is from my 71 C20 (same as a 72) (and note that the larger (1/4") line is for the drum circuit; the smaller (3/16") line is for the disk circuit):

[NorCalC20LWB]

Thank you Jocko, that is exactly what I was looking for!