Homebrew - setting a specific version of node on osx

Question

I am trying to set a node v 8 requirement for my new project (because I want to use react-redux-firebase generator, which requires v8).

I am having trouble following instructions on SO and Homebrew -they seem be out of date.

I currently run node -v and get v 10.13.0.

brew unlink node returns

Error: No such keg: /usr/local/Cellar/node

brew search node returns:

brew search node

==> Formulae
leafnode            node                node@6              nodebrew
libbitcoin-node     node-build          node@8 ✔            nodeenv
llnode              node@10 ✔           node_exporter       nodenv

brew link --overwrite --force node@8

Linking /usr/local/Cellar/node@8/8.12.0... 
Error: Could not symlink lib/node_modules/npm/.mailmap
/usr/local/lib/node_modules/npm is not writable.

I can't use sudo on this command because Homebrew no longer supports it.

Does anyone know how to get node v 8 to run?

Everything I try returns results that say the current version is 10

brew info node

node: stable 11.1.0 (bottled), HEAD
Platform built on V8 to build network applications
https://nodejs.org/
Not installed
From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/node.rb
==> Dependencies
Build: pkg-config ✘, python@2 ✘
Recommended: icu4c ✔
Optional: openssl@1.1 ✘
==> Options
--with-openssl@1.1
    Build against Homebrew's OpenSSL instead of the bundled OpenSSL
--without-icu4c
    Build with small-icu (English only) instead of system-icu (all locales)
--without-npm
    npm will not be installed
--HEAD
    Install HEAD version
==> Analytics
install: 343,912 (30 days), 946,087 (90 days), 3,815,131 (365 days)
install_on_request: 254,231 (30 days), 699,371 (90 days), 2,669,901 (365 days)
build_error: 0 (30 days)