Building a stand this weekend

[Jaws]

One more quick question: If my tank is 84" Long by 36" Wide, based on the stand I'm planning on building in the link, should the edges of the tank sit on the edges of the 4X4 posts or the outside perimeter of the 2X6's? So for example, forget that I'm planning on over extending the edges so I have a platform to walk on, should I build the stand to be the exact same outside dimensions of the tank 84" Long by 36" Wide, or should it be 87" Long by 39" Wide when you take into account that the 2X6's add an additional 1.5" on all sides?