OOps, I'm on the wrong page. Thanks for the wake-up
For; in the wells, I think you're right; it seems to me BluNblu did the homework and found 255s to be the limit.
Back in the 70s,I got G60s under my 70Swinger with airshocks and tires not quite in the wells. Those G's had about 8 inches of rubber on the road, about same as modern 275s. Ima thinking a G60-15, and a 275/50-15 are very similar in size and tread-width, but not same in section-width.
For OPs application, I got nothing against running airshocks; it's either that, or tubs, or reshaped wheel arches; on a budget, they seem to be the best choice.
Moving the springs and custom offset wheels still apply. I found narrowing the rear to run standard offset wheels nearly as economical, and now I have a much broader wheel selection available.
On the street,I like a slightly stiffer spring with a slightly softer shock, a SureGrip, and a traction aid..
There is something to be said for de-arched springs that are nearly flat; namely, the back end stays put better between the quarters, when going into the turns too hot.
For me,tall skinny tires have worked better in straightline; while slightly shorter fat ones work better in the turns; but with softer springs, and a reduced ride-height,the shocks have to be working. You'll know when things are getting right, when the back starts staying in the back, and you can start using more than the primaries in the turns without wiping out. Nothing gets me cooking like a full-lock, full throttle, around a turn in second gear, and coming out the otherside still pointed in the right direction.
But Darts just look so great with a tail-up stance, hence the airshock statement. So you can look muscular on cruise night, and the rest of the time, get busy.
