Originally Posted by North of 40
Here is are a few photos of the stabilizer bar that I will be installing, along with a photo of the correct mounting block that I don’t have, very rusty, as well as a photo from the parts manual.

Gord, thanks for the attachment, I’ve never seen that configuration for these trucks, but makes sense.
That is the 1947-1950 factory sway bar with GMC cast brackets on it.