Tire sizes on stock rallye wheels.

Sigh. A 245/60/14 is not supposed to be mounted on any rim narrower than 7". Stock rallye rims are what? 5.5"? No more than 6" wide for sure. That's not a little bit of a difference. All here in black and white
https://www.tirerack.com/tires/tire...te Letters&partnum=46SR4RADTARWL2V3&tab=Sizes

Tires aren't there just to look cool, they're there to keep your car on the road and they are a safety item. With a tire that's a minimum of one inch, or maybe even 1.5" too wide for the rim you're mounting it on the tread patch on the road will not be the correct shape/profile which will reduce both traction and tire life. Not to mention handling.

You'd get better results with the 225/70/14. Even it's supposed to be mounted on a rim at least 6" wide.

And yeah, clearly "people have done it". Well, "people" do a lot of stupid crap and get away with it. The ones that got lucky are still around to tell you it's ok. And with these cars it's hard to say, maybe the guy telling you it's ok doesn't even log 500 miles a year and only drives to Dairy Queen when it's sunny and warm. That's not gonna tell you much about tire performance is it? You're supposed to replace them at a minimum of every 10 years too, is 5,000 miles gonna tell you much about tire wear? It won't. The tire manufacturer's recommendations are there for a reason, I'm sure they'd love to sell you a bigger, wider tire if they could because it'll cost more.

245's are also pretty tight on a Dart with the springs in the stock location. They will fit a lot of them, but not ALL of them. Being squeezed down on a narrow rim makes the fit more likely, but it's not a gimme and the backspacing has to be correct.