After receiving access token, can't make authenticated request to Google OAuth 2 in Nodejs

I really hate to beat this dead horse, but I couldn't find a clear answer using node without using node-oauth. After receiving a user's access token in the Oauth dance from Passport, I can't seem to actually perform a successful GET:

function(accessToken, callback)
{
    var request = require('https').request(
    {

        host: 'www.google.com',
        port: 443,
        path: '/m8/feeds/contacts/default/full?alt=json',
        method: 'GET',
        headers: 
        {
            Authorization: 'Oauth ' + accessToken
        }
    },

    function (res) 
    {
        console.log(res.statusCode);
        callback(JSON.parse(res));
    });

    request.end();
}

I get a 401. I know the accessToken is valid. I'm using the headers the exact same way I saw them in Google's Oauth Playground. Thanks so much for your help!