Hi Mr. R,
I gonna say something & I just want to be sure that you're aware of this before you go chasing bad expensive shocks. I don't mean nothing smart a$$ by it.
On T-verse leaf spring cars, if you suspend them and then compress them it it is normal to measure differing ride heights before and after the suspension resettles or has become loaded again because you drove the car. I hope I'm expressing this right.
Our shocks normally leak as a result of the method of lubrication for the shaft. So oil build up over time is normal. Now I'll hasten to add that it is a minute quantity of oil, but unless you wash your shocks everytime you wash the car it could look like a bad leak if you are really noticing it for the first time. I'm sure you know if it is porposing. That's how I figured out that I needed to spend $725.00 for new shocks. They were pretty oiled up, to me, but not by the book.
I don't have my FSM handy and I know somewhere in there is the ride height table.
Tom