they are just to get her home after the swap is done, and only cost 15 bucks with u-bolts. I told her there are issues with aluminum blocks. I have run a 2" set before when they first started selling them at autozone, and they shot out after wearing out a couple months later. pointed the pinion straight up in the air. I was on the con, and had to change the ubolts on the side that shot out, and run with no block, tightened the other side that was going to go next and limped it to the bowl to remove the second. I tighten my ubolts before and during every run, and they still became a issue. parts suppliers swear by them for lowering truck, but I would expect the same results even after seeing it on my brothers 2wd s-10. she didn't have 75 bucks last week for the steel blocks with u-bolt kit. I was going to buy her one, but it was either buy her blocks, or use 55 of the cash I had on me to get a honda out of my shop.
les schwab sells steel blocks for 45 bucks (pair) if i remember right and they are the good ones too.