I'm using the stock T4 clutch cable from the original motor and transWe are going to need some more info. I personally have changed the clutch and cable several times. I was using the stock bell housing.
A picture of the fox bell would work from the rear. I don't know if there is room to get the cable in the hole or not but assume so as you said above that you're having problems getting adjustment out of the cable. So I'm assuming you've had it in there.
Does the cable slide back and forth easily? If so I'd still spray some graphite lube in there just because.
install the cable through the firewall and hook it up to the pedal. I'd make sure there is a plastic bushing where the cable goes around the pivot. (I couldn't find a replacement and used an "anti-short bushing for MC cable" got it from my local home depot. Just ask the guys in the electrical department. It'll be little and red and come in different sizes. It worked for about 10 years. Oh, and beware the exhaust manifold/headers. The cables burn/melt and then you'll need to do this over.
Take all of the adjustment out of the cable. (turn the blue adjusting knob toward the rubber casing on the cable.)
Now thread the clutch end of the cable down to the bell and through the hole of the bell. Put a nut on the cable on the rear side to hold it in place.
You should be able to put the cable "ball end" through the fork. Push the cable slack back through the cable sheath towards the firewall. (it is really helpful to have another person up at the firewall and start taking the slack out using the Blue adjusting nut while you make sure the Ball end of the cable stays where it should be in the fork.
Keep going. I've always liked the cable to be so tight that I pulled on it very hard and had someone using a properly sized wrench to crank it down. I'm not the only one because as you can see the the firewall tube is busted up where the teeth from the blue nut are supposed to sit. They all are.
Your done. Go for a ride.
A problem. I used the spec clutch replacement. In that case there is a significant difference in the depth of the pressure plate and I had to "shim" up the adjustment at the firewall to give me more adjustment. It worked. I think I used some Heavy duty washers. If you're using a stock fox clutch I don't know if there will be a problem.
We can't get the other nut on the back side where the spring is and the other nut doesn't turn, so what I'm understanding is we don't need both nuts and tighten the one nut up and that should remove all the slackCut that spring. It will bind when prressing the pedal in. Either remove it or leave about 1/3 of it like I did. It is really unnecessary once you adjust the cable properly at the firewall.
The cable is not sitting at 90 degree angle to bell. Is the bolt tight? Almost looks like the spring is hanging up on threads. If you cannot get it tight add a washer or something. There is a lot of force there and over time it will wallow out the bell as well as work that nut loose.
What exactly is happening? Is clutch slipping? Staying engaged?