Flaming River Power to Manual Adaptor

The top on the box coupling is held on by a bottle cap like crimp. It don't take much to defeat the tiny little pin keeping the guts in the box either. You know all that now. You're not the first to empty the box. I've never seen the couplig parts crack/break though. Reassemble or kit rebuild your coupling. Struggle with how to recreate that crimp or just buy the formed wire retainer to hold it together ( available at ebay ). Install aftermarket shaft adapter that solves both shaft length and spline size differences.
You want to center the coupling guts in the box to accommodate chassis flex. It aint got to be perfect but somewhere close. Mount the column at upper support. You may need to adjust firewall plate location on column tube. All this and more is in very a recent thread.