An interesting question. But really hits at the concept of par. It is not the fact that they are par 4s that make the holes difficult.
If I had said "My home course finishes with three par 5s that are ridiculously short (461, 422 and 482)..." would that change things? How about "My home course finishes with three par 3s that are ridiculously long (461, 422, and 482)..."? It would have no impact on the score carded by anyone who has ever played the course. I would still shoot whatever I shoot, and so would everyone else.
The holes are challenging golf holes because if you play well you will get the little white ball in the hole in a lot fewer strokes than if you play poorly.
Points well-taken, Matt.
(My only real point was: 483 never was, and never will be, a "moderately long" par-4 for me, or for almost anyone I play with -- unless it were 483 yards off a cliff!)
My answer would be: Yes, "par" does change things! Of course it does. A 483-yard par-4 is different from a 483-yard par-5. How could it not be?
I'll put this as simply as I can: The par tells me what "success" (or, possibly a better word: competence) on the hole requires.
And furthermore: I don't believe that you would play a 483-yard par-5 the same as you'd play a 483-yard par-4, if you played it 50 times (number out of thin air; 10 times, maybe).
And I don't believe your score would be the same over those 50 playings.