I dont know about that. My old truck had the stock F150s (from a late 80s to early 90s ford F150 using the 2.5 inch winde springs) and i did not have a lift block, i had a 3 inch body and 5" skyjacker front springs and wit hthat combo my rear end only sagged about an inch in the rear then the front did. The ride quality and flex was much improved over the 5" skykjacker rears taht were in that thing.
There are a 2.5" and 3" versions that were under those trucks.
hmmm I thought you did? maybe on the runner? I know there is a build on here somewhere with f150s and blocks, I could have sworn it was you.