OK, you know the towers that bolt to the motor mounts? Well there are 3 bolts that bolt them to the cross member. A few of mine are loose but i try to tighten them but the whole bolt turns and the cross member is fully boxed, so how do i tighten them?

 

I have 2 '68's and both have a slotted access hole on the bottom side for the 2 bolts across the top and the lower bolt has it's own recess for access... They take a 9/16 socket to tighten.

 

correct