http://www.usfirst.org/sites/default...CTIONSEPT6.pdf
There is a (1x1-1/2") wooden post inside the goal 13-5/8" tall. The overall height of the goal is 17".
I'd say the cost of the goal is low enough to buy the parts and try it empirically (or you can stand in the aisle at Home Depot with racquetballs).