Stiff suspension after replacing shocks/struts

I'm on my third set of shocks and struts. One, to stay ahead of them failing, two, and more importantly is I don't like surprises on longs family hauls with luggage and a cargo basket attached to the trailer hitch.

So, I replaced all four corners of the Expy with what I thought was OEM from Ford. Com using my VIN as a source for the proper parts.

After installing all four corners, I took my vehicle out for what I thought would be a standard test drive to make sure I had to creeks and rattles. Well, the suspension felt like I'd just installed a lowering kit for a low rider with absolutely no give as the former very comfortable, compliant ride I'd been accustomed to for the past 10+ years for so.

I chalked it up to a new setup that with some miles it would soften up. It's been 18 months and I still find myself cringing when approaching a bump or imperfection in the road as my 5-ton Expy hits the imperfection and it's felt throughout the entire cabin. Worse is the absolutely stiff unforgiving bump of the rear end where there's no substantial weight to at least counteract the bounce as the front end with the heavy engine.

I'm now afraid of going back to ford. Com and ordering another set for all four corners and have the same issues after handing over $900.00+ again.

any suggestions?