On a '94 Ranger can anyone confirm which port on the master cylinder is for the front brakes? I think it's he one nearest the firewall but I'm not sure and cant find any diagrams that spell it out.

 

I've thought about this a bit. When they bore the master cylinder, they have to account for two diameters of piston. The calipers need a certain volume of fluid to move, and the wheel cylinders need their specific volume, which is a lot less. So, when they bore, the smaller diameter will be deeper, towards the front, the larger to the rear.
I think every vehicle that has front disk brakes has the rear port on the master cylinder connected to the calipers. Flat. Period. Done.
Unless they bore from the front and put a cap on the master...
tom

 

Thanks for the feedback Tom.
Yeah that is my thought too and it seems to agree with how the original brake lines were routed on this truck.. I spent some time reconstructing the old lines after posting this question yesterday and it appeared the calipers were attached to the rear port of the master cylinder as you would expect.
Interestingly enough there doesn't appear to be a separate proportioning valve on this truck, one port of the MC goes straight to the RABS module and on to the back of the vehicle and the front calipers are fed directly from the other port of the MC.