Demon Rear Wheels

How much work/money do you have to spend?
I put N50s on mine, back in the 70s.........but I had to lift the back up a bit.......
275/60-15s on 8.5s fit my stock tubs with 4.5 bs, (I mighta had the springs moved by that time, not sure),
I put 325/50-15s on 10s,into the factory 68 Barracuda tubs .......but that wasn't a bolt-on.......lol, I narrowed the rear and moved the springs . This is the best way, cuz you can use whatever wheel you want/like. I highly recommend you not try 325s; they were an extremely tight fit, with a lot of massaging, in my lowered Barracuda, and I cannot fly around the turns with them on,but........... Dang do they look good in there.
But I take the 325s off and install 295s, and then it's business as usual.These are also on 10s with 4.5bs. I like the look of those 70s ETII type wheels, and have quite a collection already.295s want a wider wheel, but I have found that at 24psi, I can get good treadlife out of them. But it does roll over the sidewalls on fast turns, giving me some rear steer, which I have gotten used to and now actually wait for it and use it,lol.

So what you do is take the rear end right out,springs and all. Then put your wheels and tires of choice in there, and drop the body down to your desired ride height. Then center the stuff up in there, and drop the body another 1.5 inches, for suspension travel,and the readjust the wheels as may be necessary. Next, you measure between the wheel mounting surfaces, and write that down. then you subtract 1/2 inch in case you screwed up. And finally you order your narrowed rear end to that spec.but with loose perches.
When it come in, you move the springs and rough it all in, again centering everything.Then if the wheels rub...it will be on the inboard side, and you just install some spacers. But if you had screwed up to the outside, you would have had to roll the lips.
And finally, you set the pinion angle and weld the perches in.
That's how I did it, and thank goodness I made the rear end that 1/2 inch narrow.