The Connection Board

BUSBAR IMAGE Click to see image with one busbar removed.
The busbar is a great way to connect elements. And there are a lot of ways to do it (more info). Here we have attached the element leads to the bolt stacks. Then drilled a copper bar to fit the bolt positions and dropped it in place and bolted it tight, Then the power is attached at the bottom end. This all makes a very rigid and solid set of connections. I recommend contacting McMaster-Carr to purchase copper busbar stock (use 3/4" x 1/8" thick for up to 100 amps).
With a kiln of this size keep in mind that it could easily be wired using #6, #10, and #12 gauge wires. Here is how that works: (reference image).