I have a 84 with a 13b with 126,ooo miles and i was going to do a rebuild and i was wondering what i need to do this

 

Depends how much money you want to spend. At the very least you'll need a seal kit and you should always replace all the springs, the oil control o-rings and front and rear main seals. You can then measure and inspect all the parts and decide what needs replacing or just go ahead and buy all new stuff. I'm a firm believer in replacing all the hard seals, but the rotor bearings rarely show signs of wear and the main bearings can often be re-used also. You may also need new rotor-housings and you should always have the side housings machined.

 

i think revhed pretty much covered the important points. the only thing i would add, is if you do end reusing hard parts (like apex seals, side seals, etc ...) just make sure to make a note of where they came from on that rotor, so you can put them back there (assuming that they are within spec)

also, just as a side note, before you put the motor back in, it's probably a good idea to flush the radiator, oil cooler and use a NEW water pump.