Since you already bought them, you'll probably be alright.
I'm using them but knowing there is something that fits so much better for not that much more money sucks. I feel like they were a compromise on quality, but a good price.
For the front, just make sure to check for clearance throughout the travel of the suspension. I'm pretty sure mine would only hit when the suspension is a full droop.
For the rear, you will probably be able to get the mounts mounted by offsetting to one side. I made some plates to clamp the mount in place instead of having to drill a hole so near to the edge of the trailing arm. I have 4/6 drop and it is undoubtedly the lowest hanging part of my truck. Can't wait for it to collect some road debris and see what happens...
edit: found this pic of the rear install -
http://67-72chevytrucks.com/vboard/s...5&postcount=11 not on mine, but similar to how the instructions say. One bolt ends up uncomfortably close to the edge of the trailing arm.