This is the longest of the suggested routes at 236 miles but there are opportunities to shorten the route if you feel the need to along the way.
The link below will take you to a live Google map and detailed directions.
When leaving the campsite head for Stirling then Callander on the A84 and head north for Lochearnhead and Crianlarich when the road becomes the A82. Carry on through Tyndrum and stay on the A82 across Rannoch Moor and through Glencoe.
At Ballachulish join the A828 and A85 heading for Oban. Leave Oban on the A816 heading south for Lochgilphead then on the A83 for Inverarry. Stay on the A83 down the "Rest and be Thankful" to Arrochar and Tarbet. Continue now on the A82 to Balloch. At Balloch take the A811 to Drymen then Kippen, Stirling, Linlithgow and back to the campsite.
Here are a few links to information about places along the route
https://www.thegreenwellystop.co.uk/
http://www.nts.org.uk/property/glencoe-and-dalness/
http://www.visitscotland.com/info/towns-villages/oban-p235801
http://www.visitscotland.com/info/towns-villages/lochgilphead-p235321
https://www.visitscotland.com/info/towns-villages/inveraray-p235311
http://www.visitscotland.com/info/towns-villages/balloch-p235111
LINK TO GOOGLE MAP