Greetings from Michigan

Hello from the enchanted mitten.
I'd like to say Hi to all the group members across the globe.
Two years ago I acquired a '99 VS800 and a '98 VS1400 that a friend of mine had stashed in his basement for years.
I've finished restoring the 1400 and am about to start on the 800. 
It was setup as a bobber, and has an oversize front rim and tire.
I am looking to place a very fat tire in the back, and maybe a spring seat to complete the look.
My first question is: will I have to replace the swing arm and rim to fit a large tire, or just stick to the OEM?

Welcome to Suzi800 Chas.