Problems
 

Just got 4.10 gears installed and my cat back exhaust. Before i had these installed i was running 10 flats in the 1/8. Now I am running 9.8. i thought with all this, i would be running better. I have an AOD and when i have the pedel to the floor and try to shift at 5500 it won't shift and keeps on going up to like 7000 until i let up and then it shifts. It shifts fine if i am not on it. Is this my trans and around how much would it be if i had to get it rebuilt. Thanks for all the suggestions.

You will probably be much faster when you get the thing to shift. If the trans is in good shape ( how many miles are on it?) If internals are good go to www.lentechautomatics.com and check out their valve bodies. They are definately the way to go. If you have to go rebuild stock is about $1200 but you need to check out the whole site while your there Lentechs prices are up ther but probably the best product youll get as far as AOD
Bill