in australia, we can only get body lifts approved/engineered and legal for road use if they are made out of HDPE (hard plastic) or engineering grade aluminium. the HDPE needs to have a cruch tube through it. 2" is considered max for safety.
you will need to work out a way to use the above/aluminium blocks with the body studs. if you use the aluminium, you will need to tap a thread through the middle, and screw them on to the body studs.
if you use 2", then you might need to cut some of the threaded studs shorter to fit the block. you will then need to source some HT bolts, that will go up through the chassis mount, and screw into the bottom of the BL block.
the block should go hard up against the body, and the rubber isolaters between the block and the chassis mounts.
for HDPE, you should be able to get something that resembles a sleeve, which is threaded though the middle. it may need to be about 2" long, therefore you can screw 1" of it onto the body stud, and the other inch will be for the bolt. i am unsure of what this is called, and i dont have a pic to show you. basically, it lets you screw 2 bolts into each other, end to end.
yes, it is more complicated, and yes, it will be more expensive, but it will be stronger if you do it right. thats why these two are the only approved methods, and this is also how the kits are in aus.
i use box section, 3"x3", and of thick wall. i dont see how this will ever bend with off roading, or normal day to day driving.
maybe if i were involved in an accident, the body might become an escape pod and leave the chassis if the box decides to pull apart. i highly doubt it. i have seen rigs roll over and the box section usually holds up.
i have the 4 mounts between the front and rear tyres facing out, and the front and rear mounts, facing the opposite direction. i guess if you have them all facing the same way, there may be more of a chance that the box will flatten in the one direction.
hope this helps.
