This is how I did mineI put mine on the AEV Hi-Lift mount that goes on their tire carrier, where a pull-pal would normally go.
I have them locked on with a cable lock - a padlock would work well too.
I fit two of them with a high-lift and Titan gas tank.
I'll bet 4 would fit no worries if you didn't have a hi-lift on there.
I'm going to do a full write up with pics and details in the next week or two on exactly how I did it.
-Dan