EA82 Heater Core

Got a replacement heater core for my '91 L series EA82 Wagon and before I pull the dash some advise would be appreciated, the core on the one just purchased has inlet/ outlets at 90degrees and and 180 degrees, guess that would be one faceing fire wall and one t'words floor, both on same side of core, whereas the only guide I have in my manual is for an '86 that shows inlet/ outlets at opposite ends of core. So I guess the question is, anyone pulled the core on a '91 Wagon and doe's it sound right. The core has plastic ends that I am told split, thus causeing a common leak problem.. Just a pain to get to, so want to get it right first go. (If it's the split plastic, perhaps Devcon would result in a spare at some future time).. Many thanks.. Lang