Upgrade to 2.2 from rooted 2.1?

[durangojim#AC]

I've done a couple searches but can't seem to get a straight answer. I have a rooted stock 2.1 on my Incredible. Works great and I've installed the wireless tether app. If I download the official upgrad.zip file and upgrade, will this work or brick my phone? I don't have clockwork or any other rom managers installed.
Thanks and sorry for asking, but I couldn't get any good answers in my searches.

 

[bigslam123]

How to get Clockwork recovery, busybox, & root on 8/26 leaked RUU 3.21.605.1 - xda-developers

How to get Clockwork recovery, busybox, & root on 8/26 leaked RUU 3.21.605.1

 

[Jacksonroh]

I was rooted and did the update and my phone won't stop restarting and when it works it's really slow.