Instead of a solid wood block how about 2x12x12 You need six. the size I gave will need to be adjusted a bit
NOTE teh 12 inch length will need to be adjusted
The top i a full piece (12 x 12 showing
Under it are two pieces 12x12 and 2 12 by 9 (the top piece lies ATOP the 4 sides two sides need to be short enough to go between teh end pieces)
The bottom piece is 9x9 3" screws hold it all together. At least 3 per edge/end of piece of lumber
Lighter than a solid box by half or more but Well. that box should support about half a ton no problem (I'm guessing based on somethign I built like it)
