Differential drop specs

So I bought a 3/1 toytec lift for my truck. I enjoy making parts and items when at all possible. I work as a machinist and I figured I could save a few bucks buy making my own diff drop spacers.
Does anyone know what the correct thickness they need to be? I have plenty of 6061 aluminum rod stock to work with and I should be able to turn those out fairly quickly if I knew what the measurements were.
I can always just wing it and I'd probably be fine, but I'd like to be sure.

 

I made mine, 1.0 OD X .750 X .625 ID

 

Thanks man! Exactly what I was looking for.
Also, you may know, do I need to drop my carrier bearing too?