The tailgate moves both ways on C bodies at least back to '65. Sounds like the lock solenoid is stuck.

Rob '70 Fury III 'vert (GT Clone)was 318 3 on the tree,now 440 automatic '68 300 2 Door HT vinyl/cloth bench '68 Newport Custom 4 Dr. HT, 383/2, FULLY LOADED! '68 New Yorker 4 Door HT, 440/Auto, loaded! 2004 Chrysler 300M Special daily driver