Box scrapers really are for grading rather than transporting. Unlike highway scrapers, a box scraper is similar to a blade with end plates to keep dirt from coming off the blade ends. The bottom is open.
You can scrap a box full and then drag it somewhere else. However, dragging is usually done from one part of a grade you're working on to another part. This type of operation requires many adjustments to the top-link to control whether the scraper cuts, drags or spreads. Often adjustments are required on the fly, and a hydraulic top-link is almost an essential. Even so, these separate operations at best are not completely clean. A blade set at an angle for dragging will still cut and spread here and there. The 600’ between the two locations would certainly get tore up.
Box scrapers are useful for all sorts of tasks, but I don't think one is going to work well in this particular case unless a road is being built between the two locations. In addition, as Bird noted a 4' scraper is certainly as big as you'd want. However, the box of a 4' scraper really doesn't hold much. Moving a significant amount of dirt 600' would take many trips.
If the tractor has a loader, the easiest way might be to rent or borrow a dump trailer and use the loader to fill the trailer. Of course, using just the loader would work but would take many trips. Without a loader, the best alternative might be to get a 3ph scoop (mentioned on CTB). The cost of a scoop is almost low enough to justify the purchase even for a one-time use. However, when looking for implements for a small 14hp tractor, make sure the 3ph mounts on the implement and tractor are CAT1 and the lower 3ph arms can be spread wide enough to mount the implement.
