varying lengths of conveyors 15 to fit varying lengths of truck bodies since material forward of conveyor 15 can be spread after shifting it aft against tailgate 20 there is no need for conveyor 15 to extend all the way to the forward end of body 11 this allows my spreader 10 to be made in one standard size that fits all dump bodies it also keeps conveyor 15 relatively short so that it can be driven with moderate power has a small frictional drag and requires minimum length replacement chains or belts conveyor 15 is preferably pinned to the lower rail 21 of tailgate 20 by a pin 19 passing through brackets 17 on conveyor 15 and rings 18 welded to bottom rail 21 opening 12 in tailgate 20 extends down to bottom rail 21 where it is flush with bottom 13 of body 11 so that conveyor 15 rests on bottom 13 and extends loosely through opening 12 just above bottom rail 21 when tailgate 20 is closed pin 19 allows relative pivotal motion between tailgate 20 and conveyor 15 and also makes conveyor 15 move with tailgate 20 as it pivots open as shown in fig3 any unspread residue ballast or even an entire load can be dumped from body 11 through open tailgate 20 with spreader 10 in place as shown in fig3 this can be important on many occasions unspreadable lumps that remain after a spreading run can be dumped at a loading station ballast desirable for safe operations can be returned to a loading site and body 11 can be emptied of whatever it contains for filling with a different material or for removing spreader 10 another advantage of pivotally connecting conveyor 15 and tailgate.