The problem with the wheel well is at the top. When the tire goes up into it, it tears the side wall, ask me how I know. Pushing the tire that you have out will definitly be a problem, 250 or not. What alot of us do is roll the lip, but that doesn't really help if the tire is past the edge anyway.
I moved the pics to my thread about my new 70. i counld not figure out how to post them in two different places.
I have been working in the tire business for a long time and I'm always asked what would look good on the vehicle, and I always answer "what do you want your vehicle to look like ". I'm not the one to tell you what to put on your car. If you like it jacked up in the back, or lowered to the ground or you want to keep it stock. As long as it fits and clears your fenders, GO FOR IT!! Go for what you like, not for what others want. I came across a set of centerline wheels some time ago. They where 15x12 with 295-50-15 for the rear and 15x8 with 215-60-15 for the front, they came off a 72' march 1. I put them on my 72' maverick and they looked awesome !! I eventually took them off for clearance problems. I had to put two extra leafs springs and air shocks and I didn't like the ride. Do some research on offsets and stuff. Sometimes you have to try different size tires to find the look that you like. Good luck and have fun !