Tie rod end advice

1994 GMC Yukon, 5.7L v8 350 throttle body injection 4WD, 117,000 miles approximate.

I took out my old inner and outer tie rod ends to replace them with new. I have been following instructions provided by the Hayens auto breakdown and rebuild book and it tells me that when replacing both inner and outer tie rods, the thread difference of the inner and outer rods should be no more than 3 threads max. I counted my old rods and they are 9 for the outer and 15 for the inner. 6 threads difference. Please advise me on which rod to add more thread to because the alignment shop told me if it is too much apart they will also charge for tie rod reassembly along with the alignment. Also, if it drives well and is aligned pretty close, do I Really need a professional alignment?Thank You!