727 2nd to 3rd flare up

i have just put together what i had wanted to be a daily driver a 67 fury (not an a body but looking for help) the issue i am having is a flare up or hesitation to shift from 2nd to 3rd

i have just put together the car and have not had it on the road that long but the problem has started after 3 or 4 weeks of driving my kick down was adjusted using the wide open all the way back method and worked fine untill recently i have tried moving it in and out with no change other then the 1st to 2nd shift getting firmer or softer and 2nd to 3rd also changes but it is still behind 1st to 2nd in feel as of now to get a proper 2nd to 3rd shift i have to have my kick down adjusted to a point where 1st to 2nd feels like i have a hard shift kit and 2nd to 3rd feel satisfactory also at this adjustment i cant achieve wide open throttle since my kick down wont allow it to move

i have been told to do a quick band adjustment to see if it helps i was told the one on the outside of the case handles 2nd and 3rd i was wondering if this would be a good recommendation

also this car was sitting for almost 5 years apart with the trans drained i just put in a rebuilt 318 and used the trans as is since the pan looked good and clean so i slapped a filter in and filled it with dex/merc

most mopars i have or play with are all 4 speeds (i can set the kick down and gear shifs on them all day:D) but when it comes to the autos i have no clue where to start on repairing them