Transmission problems????

Picked up my car this weekend. Sat for 4 hours with my car off on I95. What fun. Raining too. Not the drive i was looking forward to after not really driving my car for the last 7 months. I did manage to get a great pic of my car in the rain at a rest stop. Paint looks orange at night kind of wierd. I will post pic later.
OK to the point. In overdrive between 45 and 55 car is sluggish. doesnt feel like the trans is slipping. It is really hard to expalin. I know overdrive is for higher mph but i dont remember it losing alot of power anyweher in the rpm spectrum before i left. Which is wierd. It was hardly driven while i was on my 6 month deployment. Is there some sort of adjustment for the overdrive in a 700r4? It kicks down fine to third when i step on it. shifts smoothe when going slow and hard when on the gas. If anyone has had a similar problem or has any ideas or can help in any way that would be great.
I am still going to put in the 373 gears holley street avenger 670cfm carb auburn pro series rear and new fuel pump. I will deal with the overdrive problem after all of that. I cant wait til octobert so i can put all the parts on. Us not so rich people have to save money for the parts and more money for installations. I will be helping with the mods. I dont claim to do things i have no idea how to do. Ok this post is a little long. I have been on vacation for the last 20 days.
sorry for the long post

toight. but i dont think you have a tranny problem, i think you are just in overdrive and like most people in OD, dont have much pickup. you might be able to clean your injectors or use some fuel additive, but i dont think you are going to see a difference til you put them gears in...