Depth Under seat for sub box?

[muddpile]

I have decided to keep the gas tank behind the seat. It's easy to fill up there, it doesn't leak and it's just less work to leave it where it is. That means, however, no room for back there. So my question is this: How much space is there under the seat. I have a 72 with the stock bench in it. It is majorly cold here right now and there is a lot of junk under my seat, so I really don't feel like measuring it and I figured that someone here might know. I would like to know how big of a sub I can fit (8", 10", 12"?), how deep the space is and how much airspace there is under there. I would likely place the sub on the passenger side and the amp on the drivers side. I would assume nothing would fit on the tranny hump in the middle?

Also, how big of a component set have people done? Will 6.5" work with a separate 1" tweeter or is only 5.25" possible?