aluminum lifting blocks

[codeman 6.0]

I just put 3in aluminum blocks on the rear of my f-250 i was wondering how much weight they can hold. I heard that they collapse, is there any truth to that.

 

[StrokerDude]

I wouldn't put a lot of weight in the back of the truck or tow anything. Especially if they are not solid. Wouldn't be too bad if they are a solid block though.