the difference between left and right upper control arm

I have a 1976 c3 im working on and was wanting to know the difference between the left and right upper control arm, its a frame off restoring from the ground up. I have replaced the upper and lower ball joints and was wanting to find out if there is a difference between the two  

both left and right upper and lower control arms are different..      

on the upper control arms...   they are triangular..   one side is straight.. one has a slight curve...

the straight side goes toward the front of the car..

it is also really really important..  that you NOT tighten the bushing bolts with the suspension hanging..  the bolts have to be tightened (torqued) with the suspension at ride height..    

if they get tightened to the frame or shaft with the suspension not at ride height.. they will have very short lives.. as they will be at or beyond their normal twist when the car is set down..

think of the rubber bushing.. how long would it live if it is twisted to the point of tearing when you install it..

installing them and leaving the bolt loose.. until you get the car to final ride height..    just as long as you post a BIG note.. on the garage door.. the steering wheel... the windshield..  tighten suspension bolts at ride height..

you might have to lower on some blocks to get enough room under the car to reach the suspension bolts..  or do it on a drive on lift.. like they have at a muffler shop...