That's a good question.. I haven't measured them. I have a 241 in my crawler that I can measure. or I'm sure I can google a 231 dimension.. I don't know how narrow the frame is as I haven't brought the truck in the shop yet to do preliminary measuring for stuffing of 10lbs of shit in to 5lb bag..How wides a 231/241 case? Frames on these are narrow. My 208 is tucked in the C of the frame