727 doesn't shift into second gear like it should

I guess I would tend to think a good trans guy (not saying yours isnt) might set them more on feel then specs. Everything ive read and all the videos Ive watched are atleast 2 turns. That band can be adjusted with out removing the trans from the car or removing the pan for that matter. SInce the adjustment is on the oudside of the case. Mark the bolt (one with square head) loosen the lock nut. Back it off 1 turn and tighten down the lock nut. If it improves you know the problem. It not well you still have problems the builder may need to address.