80mm to 120mm fan switch over

I was thinking to switch all of my 80mm case fans, to 120mm, including the cpu cooler. And possibly mod my power supply to fit a 120mm fan. Now my question is if I go to 120mm fans, would I get same/better cooling results but with less noise. Also any cheap way to quiet down my 160gig wdc 7200rpm 8meg buffer hard drive, its really loud, and make noise when its running.
Thanks

Yes you can get more CFM with less noise with 120mm fans. Provided you stay in same CFM range that is.

Switching to 120mm fans will really quiet down your system. They can push more air at lower RPM's.

The question, is how can I fit, a 120mm, on a 80mm thermalright hsf. Is there any converters. Also can anyone suggest me, some good and quiet 120mm fans.
Thanks

it will require a good deal of support and duct fashioning to put a 120mm fan on a 80mm heatsink. much better to get a 120mm heatsink. this should go in the cooling section.

I have used these on a few of my builds. I put a 60mm to 80mm on my ladies pc last week. It runs quieter and cooler.

http://www.2coolshopping.com/Mercha...ct_Code=01-507-0019&Category_Code=01-010-0000

These work well if you have limited space around the CPU.