At least on the newer Garvin racks, there are three pairs of brackets you will need.
At the base on each side, there is one bigger bracket that gets sandwiched between the body mount puck and the tub and wraps around the outside of the tub. There is also a small backing bracket that mates on the inside of the tub. At the top of the tub, there is a smaller bracket that has two carriage bolts through the tub and a bolt for the support.
Most of the bolts are carriage bolts, I believe 5/16” or 3/8” depending upon location. Some bolts are regular hex bolts (might be flange bolts).
At the base on each side, there is one bigger bracket that gets sandwiched between the body mount puck and the tub and wraps around the outside of the tub. There is also a small backing bracket that mates on the inside of the tub. At the top of the tub, there is a smaller bracket that has two carriage bolts through the tub and a bolt for the support.
Most of the bolts are carriage bolts, I believe 5/16” or 3/8” depending upon location. Some bolts are regular hex bolts (might be flange bolts).