Ok, I'm back to working on the K5's bodymounts. I got all of them loose and some on one side the new uppers are in. Problem is the lower one on the very back. I have the rear bumper and tailgate off. Do I need to drop the gas tank to get the lower mount on in the very back? I can't see any other way to get the lower mount in the frame. It is a 90 K5 if that makes any difference. TIA.