sorry to be the bearer of bad news, but i would bet youve smoked the direct clutch (been there, replaced that) if the 1-2 shift seems timed right, and is firm enough, dont count on tv adjustment...
When I had this problem I had desplined the third gear hub....but it happened when I was shifting from 2nd to 3rd at 7k RPM and knew it was broken instantly.
actually, what dodgestang is calling the third gear hub, is the direct clutch hub.. ( tomatoes, tomahtoes...) it is used for both third gear and overdrive, depending on the o.d. band (if it has the outer diameter of the drum locked down or not, determines if you are in overdrive) desplining the hub is a common problem in the older aod's. go to baumannengineering.com, and you can read up on this problem (click on the "aod upgrades") if you have your trans rebuilt, make sure the later, stamped steel drum is used... it is a bit stronger, and it will also let you add a couple more friction discs into the stack.