The Standard All-In kit 9005 will allow you to convert your dock to a rolling dock.
The kit includes:
1x Standards wheels kit (9002-2);
2x L-Brackets (9005);
2x Legs 1-5/8'' x 4' (1111-04);
2x Leg-Holder (0005);
2x Backer Plates (0010);
1x Carriage Bolts kit 3/8''x2-1/2'' (pkt.8) (0014);
2x Caps 1-5/8'' (1114);
4x 1/2'' PVC spacers (9007-12);
2x Cotter pins (1136).
*The capacity of the weld of the brackets is approximately 500 lbs.*