SSBC disc brakes won't stop

No! Lemme think, I mighta told you wrong.Nope, I reread what I wrote and emboldened the tricky part
The first thing you need to remember is that the front most chamber in the M/C operates the rear brakes, and the rear-most chamber operates the front brakes. You do have it plumbed that way,correct?
OK then, I got it.
You have a mechanical lock-up. This is caused by how the M/C is internally built, and the fact that the rear is clamped solid.Here's what I see. The rear system has air in it.During the course of your work, the rear has built up air-pressure. The compressed air has moved the associated piston inside the M/C to a position up next to the other piston. This locks the two pistons together mechanically,and the piston for the front brakes can no longer move, and hence no front brakes. The solution is to loosen the clamp at the back,being sure to have at least one bleeder back there open. This will allow the pressure to escape. Next pump up the front brakes, and then while holding the pedal down, have a helper tighten the clamp, just enough to slow down the fluid travel at the back, but NOT ENOUGH TO TOTALLY PREVENT FLUID TRAVEL. If you refer back to my earlier post, I think you will find that this is what I wrote.
So now, we have pushed the piston for the rear brakes all the way forward, away from the firewall.Now this is not the correct working position for that front piston (which operates the rear brakes), but it will self center upon release of the pedal.And so now the front brakes will again work.If not, then the clamp is too tight,again.Try it.