What is the longest stretch of Babylonian Talmud with neither Ravina nor Rav Ashi? I heard it was 3 pages.
Neither of them appear between Tamid 28a and Niddah 8a, which is also a stretch of 11 daf. If you count Maseches Middos, which, although it has no Gemara, is printed in-line with the pages of the Vilna Shas, you get a stretch of 15 daf.
Neither of them appear between Nedarim 35 and 48; so you can go eleven pages without them.
This is the longest such stretch; many other stretches of length > 3 exist.