66 c-10 rear tranny crossmember

["66" TEXAS]

Is there supposed to be a rear tranny crossmember for a 3 speed saginaw? It has syncros and is 22 inches from the bell housing to end of the tail. Some ppl say theres not one. It only is to use the bell housing mounts for support. Seems like a lot of weight hanging from the those 4 bolts to me. I have the pre drilled holes in the frame rails to accept the crossmember, maybe it was an assy line thing where they drilled the holes in all the frames for different set ups. Sry I have pics but dont know how to post them on here.

Thanks for any help.