Pitman arm question

[Cbo68]

Afternoon all
So I did a front and rear end swap on my 68k20. I came across a great deal on a set out of a 77 or 78 k20. 14 bolt rear 10bolt front with disc brakes. Also installed a 4in lift. I bought skyjackers 2-4 in drop pitman arm to that is the style that is open slit at the end that connects to the steering shaft. All of the solid end pitman arms I’ve seen already have the ball joint pressed into the other end for the centerlink configurations. The problem is my power steering gear shaft does not have the groove to allow for the bolt that goes thru the pitman arm. Now I know I can go the the parts store and buy the correct steering box my question is do I really need to? It appears I can still install the bolt thru the pitman arm and since the shaft has splines all the way around it seems to pick up the splines in the pitman arm. However I don’t know how long this will last. I haven’t tightened anything down yet and I’m not trying to cut corners I’ll gladly purchase a new steering box just curious if anyone has ever done this and if so did it work or fail?

Steering gear box casting number is 7802644L