Robert - The outer blades on most dado sets have beveled tops on the teeth that angle in from the outside to the inside. They protrude slightly above the flat top teeth of the chippers...it's intentional to reduce tearout, but they do leave tiny grooves at the very outside of the dado....aka "bat ears". Your 80T blade likely has alternating bevel top teeth, which will leave a double groove where each 80T blade is used. You're likely to also find that the diameter of the blades are not exact, which is really just going to leave a very sloppy bottom.
In a nutshell, I wouldn't do it. Have you tried using a backer board to prevent tearout? You could also try taking a very slow, very shallow dado cuts, and work your way up to the desired depth. You could also try using one 80T blade to score your dado to just below the full depth, then use the stack to complete it.
I'm using an Infinity Dadonator set, that has 24T cutters and 6T chippers...it does pretty well in ply.