At my old shop, we got an '86 Bronco in trade for fixing a Fiat X-1/9. That truck soon became the unofficial mudboggin' truck of Sportscar Workshops. My buddy and I got a set of 40" Denmans in trade for something I can't remember, and instead of lifting the Bronco, we just removed the bumpers, and radiused the fenders with a sawzall.. Like ya do.. it had an open rear, which was embarrasing the first time we got stuck in the mud pit ten feet from the start line. Smart guys that we were, we decided to lock up the rear. We couldn't afford a spool, so we cracked open the diff, heated it with the oxy-acetylene torch, and welded up the gears.. After this modification, we trailered it to the mud pits (smart guys that we were). Before this we were driving there on '33s, swapping tires for mudding, and swapping out to go home. Punchline is, we kept the '40s on it permanently after we welded the diff. Tom, (my friend, and boss at the time) got a phone call from the police at 4:00 AM on a tuesday letting him know that they recovered his (unbeknownst to him) stolen Bronco. Sixty miles away. It had no working headlights or brake lights, it had a welded rear, at least one foot wide 40" Denmans, no top, and the back was full of beer cans before it was stolen.. The thief hadn't even been pulled over, he'd run out of gas. So, yes.. you can drive a spool on the street.
Also, I laughed out loud at "cat mashers". I've always called the varmints "wheel chocks" myself.