Here’s a list of DiscoVision releases in my collection and their dead sides:
Frankenstein (1931) {Dead side is Side 3 of Sgt. Pepper’s Lonely Hearts Club Band}
3 Days of the Condor (1975) {Dead side is Side 1 of the unreleased DiscoVision edition of Bullitt}
Jaws (1975) {Dead side is Side 4 of The Electric Horseman}
At Home with Donald Duck {2-Sided titles such as this one don’t have dead sides)