Slowy, My pedal box is not terribly different from yours and I also run a TKO600.
I found two problems. The first with the pedal box and master cylinder alignment with the master cylinder. The push rod when attached to the pedal with a clevis did not align. I had to make a push rod which mounted to the left side of the pedal to get a straighter push.
Secondly, I found that if one used the earlier clutch TOB lever which pivoted from the left hand side of the bell housing (relative to the main shaft) then the pedal was too heavy.
If one uses the later clutch lever which pivots from a ball on the right hand side of the main shaft then there was a heap more leverage and a much lighter pedal.
However, that means the slave has to be mounted to the rear of the lever.
Here is a link to the slave kit which pushes towards the front of the car for use with that type of lever.:
DazeCars, For Sale Page