My car last year began to have issues with hard brakes and stopping. My master is located under the drivers seat,. the front brakes are aerospace 4 piston calipers. I replaced the rear drums with a wilwood system. To my surprise nothing changed . so I replaced the master and all new lines. speaking with tech i did a pressure test and find the fronts pressure are 925 /725 lbs and the rears only 575 lbs. The specs should be 1050 / 1200 lbs. the pedal throw ratio is 3.44.1! as per the Wilwood web site 6.1 /or more is desirable. The only part not changed is my line lock . Im at a loss and don't understand why the pressure and stopping power is not there. needs some advise.

You need a smaller bore master cylinder to raise the pressures, do you have one or two master cylinders?
My car has single Wilwood calipers on the front (11.3/4 rotors I think)and duals on the rear end(same size rotors) I use two 15/16 master cylinders if my memory is correct, it stops well in the 1/4 mile at 150 MPH and does okay, not excellent, due to our shutdown area is short, at the local 1/8 mile track stopping from 120 to 125 MPH at WOT

Couple of quick questions... do you have all steel brake lines.. so they cant expand.. what size master..
I can tell you right now that your master is too large.. one other thing.. you said your master is
mounted down low.. is it below the brakes themself where you need anti drain back valves( pedal
needs a pump).. or is it just the lack of stopping power

You answered your own question. [ the pedal throw ratio is 3.44.1! as per the Wilwood web site 6.1 /or more is desirable.] Your pedal ratio is close to1/2 of what it should be. I agree that a smaller master bore could help but the pedal ratio isn't giving you much leverage. As Mr P suggested it needs residual valves if the master is lower than the calipers to prevent double pump.
Doug