Sudo npm install -g ionic@latest installs 3.6.1 and not 3.7 on mac

After fixing my node and running the command sudo npm install -g ionic@latest
it installs 3.6.1 on mac but the same thing installs 3.7 on windows.
My initial issue started with trying to upgrade 3.6.1 following instructions posted here http://blog.ionic.io/updates-for-all-ionic-angular-3-7-and-more/ and the problems I had posted here Error upgrading to 3.7 on Mac (windows was fine)

Don’t: ever run ionic or npm under sudo
Do: use nvm to manage node installs

never used it, always used npm before so I will give this a try.
Any good resources on learning how to use nvm properly other than the link u gave me or is that all I need?

They aren’t equivalent. nvm lets you manage different npm installations.

Should be all you need, although if you have been using sudo, cleaning things up can be challenging. Inspect your PATH carefully and try to remove any node stuff you have installed now.