Thank you both very much for your replies! I would have initially thought that such a large aircraft with relatively short struts would be a bit more restrictive in both respects. The only Boeing document I have at the moment is a rather generic PDF that covers systems and procedures, but offers relatively little in this context.
Yes LeadSled, I was actually referring to the -320, thank you for catching that. The aircraft in question has the newer-model cowlings, so I assume the roll restriction will be a little bit tighter in this case. I'll see if I can find anything else from Boeing - tracking down original versions of their training literature seems a bit harder since they switched so many of their older materials over to more "standardized" revisions that seem generally lighter on such details.
Come to think of it, I've yet to go through, in my brief career, a type rating program that volunteered these figures without my needing to dig for them. I've always had to pick the brains of the line pilots or go through the aforementioned trigonometrical workings. One would think this information would be presented with a bit more emphasis...