Lowering Blocks?

[stevewhitmore]

OK so I put new 2" lowering coil springs on my 69 to try and level it out and the rear height is the same but I have only driven it a 5 miles on a rough road and it has been 30 degree's since I installed them. Somewhere I read that the cold might make them not so "springy" but when warmed up they might lower some?
So now I am looking at 1 1/2" lowering blocks from CPP, anybody use these?
My problem is they are almost the price of a new set of springs and how safe are these blocks?

Thanks