Thanks Outlaw and old chevy.
It has 17 inch budnik wheels on it. I believe the last time I took the wheels off to polish them, the front were 8 inches wide and the rear were 9 inches wide.
I'm not exactly sure on the drop, when I bought the Blazer nearly 2 years ago, it was already this low. The front crossmember is only about an inch or so from the ground though.

I really need to 'bag it so it's not quite so low on the streets.