Does size matter?

[KB]

What is more important: the size of the heatsink or the size of the fan? I have an old Alpha heatsink I used for my Celeron 450 and it has a huge fan. The current heatsink I have for my Athlon 1.33 is a http://www.newegg.com/app/Showimage.asp?image=35-103-121-02.JPG heatsink and it has a bigger heatsink but a much smaller fan. I was thinking about using the old Alpha, with its "skirt" and ducting the air out of the PC. Its easy to do with the Alpha but hard to do with the Cooler Master and sadly I can't put the big fan on the bigger heatsink. Is the old Alpha good enough to support up to an Athlon 1.33?