8.8 rear
 

i changed the pinion seal on my 8.8" rearend (where the drive shaft connects)
and i was wondering if anyone knows if the pinion nut has to be torqued or just tightend, somebody told me it just had to be tight but i'd like to be sure before i run the car!

I beleive it's a very light torque spec which would be like hand tightening it...but I'm not certain.

It's not that simple.
There is a crush sleeve that is suppose to be replaced along with the nut.
You're suppose to torque the nut so that the new crush sleeve gets crushed, but you have to sneak up on the torque so that you have the correct pinion bearing preload.
The preload should be between 8 and 14 lb-ft for used bearings and 16 to 29 lb-ft for new bearings.
The torque spec for the pinion nut should be 140 lb-ft.
If pinion bearing preload exceeds specification before 140 lb-ft is reached you need to change the crush sleeve.