Before my amp arrived, I was wondering about this too. I had seen an eBay store selling/auctioning ampcases for Z amps, which included the inside dimensions to fit a number of Z heads, combos, and cabs... except the Stingray (I guess it's still too new to be listed?) I was thinking about getting one, but was unsure about the Stingray's dimensions.
Search "Dr Z amp" on eBay and see for yourself.
It would seem there is a uniform size for 2x12 combos, as the cases for the Prescription, MAZ, Mazerati, et al. are the same dimensions: 27-3/4" (W) x 22-3/8" (H) x 10-1/4" (D).
And, to answer your question, my Stingray combo measures the same as the dimensions above.
STINGRAY 2x12 Combo - #20 Z Air Brake - #1154 Cage 18/30 1x12 Combo Juke 112-V6 1x12 Combo Guitars? Waaay too stinkin' many!