Steering wheel upside down...

Just to help anyone with a similar problem... Turns out the pitman arm wasn't clocked properly as Dano suggested. The Firm Feel pitman arm doesn't have a master spline and I had it a couple of teeth off. Because the 'fast ratio' pitman arm was longer than standard, it allowed the wheels to turn hard left and hard right BUT the box wasn't centered with the wheels straight ahead. Once it was clocked properly, the steering wheel and tires were both straight and the tie rod ends had an equal amount of exposed threads.

As for keeping the coupler cover from coming off, I installed the coupler on the steering shaft with the column out of the car. It's relatively easy to get the cover on tight on the work bench. Then, I just pointed the wheels straight ahead slid it on the master spline with the steering wheel spokes positioned properly.

Thanks to all who commented.