Im all for saving money where I feel it is necessary. Thats the reason I still run my stock rims and with spacers for the rancho kit instead of forking out money on rims and new tires but sometimes there are places I feel you dont wanna go cheap on. Personally I would not do a body lift as I have no need to but if I was I would get the kit as it has been tested and designed. I wouldnt be able to feel safe going down the road knowing that I am sitting on some hockey pucks I got from the local sports store.
If this were something new, that had never been done before perhaps I'd agree with you, but hockey pucks for body lift is something that has been done for MANY years.
Keep in mind, you're still using the original material that came with the vehicle, but just adding to it.
We're talking about 12 chunks of a dense material (body lifts are made from an assortment of different materials, from aluminum (no WAY I'd use aluminum) to plastic) and some bolts. There's no "engineering" here, it's VERY simple.
As for testing... I'd put money (a lot of it) on hockey pucks having more miles of "testing" on them than any one of the body lift kit mfg's setups do.
Do a search... this isn't some random "maybe it'll work" kind of thing... it's more tried & true than likely any "specific" mod than any of us have put on our vehicles!
Search for "hockey puck body lift problems" or "issues"... not a single person saying they've got problems with a vehicle they lifted.
08SFH3, you got a link for those blocks you mention? I can't find them on PA's site, probably not looking in the right place.