tranny issues i think dont know what plz help
 

i have a 94 4x4 with minimal mods just an hx40 and some fuel plate and afc mods and a torque lock up switch well my deal is this the truck shifts pretty smooth through the gears but i dont think its going into over drive but when i push the od on/off switch it shifts down when i hit my lock up switch it shifts but does not drop the rpms like it did a week ago ive been told it could be this it could be that but im not sure i drove it home from work today and at 60 mph i was at about 2200 rpms not normal. fluid level appears fine. any ideas? trans? torque converter? lock up switch? bands in trans? where do i start? :s: