Introduction, and trans issue

Hello,
This my first post so I will say a little about what I have. I have a 1968 dart 318 with A-904 8.25 rear end, it is a little off but I like it. It is my first dodge ever But not my first classic. So I installed a edelbrock proflow 4 and after market lokar kickdown cable. So now I can not get the trans to shift back into 3rd after it kickdown into 2nd after I get into it. I checked kickdown and it seems to be adjusted ok, 1st to 2nd shifts at about 20mph and 2nd to 3rd about 40 ish. What do you guys think. Thank you for the help.