How do I know what gear set I have? And what would be involved in swapping the four wheel drive components from a SRW truck into a dually? Can I do that, or do I have to swap out the whole axle? I would like to know what gearing I have, so maybe I don't have to touch the back axle.

 

As for your gearing there should be a tag attached to one of the bolts on the rear diff cover that tells you what gears you have.