If it is like my Camaro, there are alignment holes as part of the forward body mounts (not the rad support). You usea dowel or something to align it with the corresponding hole in the body. Do the same on the RH one, excedpt the hole in the body maybe elongated, not round.
Hole in mount (that hole s/b round, we replaced metal in the pad, leaving the alignment hole alone):
If the frame is in the car, you can do one at a time. That is the way to do it.
Read here:
Thread at NastyZ28.com
Also, search at
www.transamcountry.com
Good luck.