My surveyors tripod has one extension on each leg. I would guess the overall height at a moderate leg spread is something over 6 1/2 feet. Of course one can adjust the extension to what point is desired. The difference on a surveyors tripod (or at least mine) from a photo tripod is that in the upper leg attachment plate exists a round hole. The size of the hole is smaller then the lower mounting surface on a Bogen 3047 head. The only thing that is required is to take a 3/8 in all thread bolt and a nut and a small 3/4 in W by 3in L plate to mount the head to the tripod upper leg attachment plate.
In the case of a post mount Majestic head an adaptor is required from the post diameter to a 3/8 in female bolt thread. The adapter that I had made has a larger lower diameter to mount to the upper leg attachment plate on the surveyors tripod.
For those looking to shoot 8X10 on one of these contraptions, The Majestic geared head works out really well. I bought mine used on Ebay. Cost new $285.00 ...used $49.00