Rear wheel options/ moving in springs mini-tub 70 swinger

Yup over a foot wide and that little 408 still roasts them
Of course, I'm sure you could get better traction out of a narrower tire if you wanted to go with a 21st century tire

I think 275s are the widest you can fit, but I'm not sure
DO some browsing in the wheels and tires section, it has been coversed there for sure