Well, here is the verdict:
Using my carbide 45 Colt Lee resizing die, I ran a few Star-Line pieces of brass through it and they fit fine; none topped out in the die and resulted in crushed brass near the top of the case, which is what I was afraid of happening.
I flared a case and seated a bullet using the rest of the dies and as one would expect, I needed to adjust the die roughly 1/4" in order to flare and seat correctly. I may use the washer trick but it's easy enough to adjust the die with my Lee dies so I'll probalby just adjust every time I switch calibers.
So, in the case there are any other users of both calibers out there; the Lee 45 Colt carbide resizer will work on 454 cases without running the case into the top of the die.
Thanks to you guys for your comments and assitance. Yes, I could have bought a second set of dies but right now I'm feeling SO GUILTY for spending the money I did on a Super Redhawk (despite getting a good deal) and loading accesories, I thought I'd cut as many costs out as possible. Not that my wife said anything to me about the purchase, but I just feel I can't even look her in the eye right now.