I have a LC GTR Torana 4 speed and I'm putting it back together and bolting up the rear gearbox member. The issue I'm having is it could bolt up in two places. I mean if I push it forward it will fit into one set of holes but if I pull it back it will fit into the back holes. There are several positions I can bolt the cross member to but which is the right one? If I use the back holes it looks like I would need a spacer between the cross member and the chassis. Any ideas?