is it worth porting anything before you get the throttle body bored ,and if is what about only porting the upper intake(because the lower one is a pain in ass to get off). Will i feel the diffance with a stock 2.8 with 120,000 if i do start porting and do all of the above a once .

To get the most for your work and money, you need to do all 3 pieces and the TB.
Especially the lower one, it will also help give you a better inj. spray pattern if done right. Have Darrell Morse do them for you.
http://www.diginostics.com/Darrell_Morse/darrell_morse.html

yes, you want to do all 3 peices (4 if you count the throttle body). the main reason for the porting is to make even/smooth transistions between the peices, not for volume/size.

Every little bit helps but you probably won't feel any difference with just porting the upper intake plenum. If you have to remove the upper plenum anyway go for it.