stock valve size
 

I have an 80 with the L-82 and i was wondering what size valves i have.

and possibly rear end gears but from what i understand there was about six rear end options

RE: stock valve size
 

I'm guessin' valves are 1.94's.
Rear end.....
get one rear wheel off the ground, leave trans in neutral.
Mark the drive shaft and the rearend housing at a common point.
Rotate the tire one full rotation and count the rotations of the drive shaft.
This will get you real close as to the ratio of your rear end.
3 turns, 3.07:1
4 turns, 4.11:1
These are rough numbers, but will get you in the ball park.