20s On my Dart

While I don't have any experience, I would imagine it probably depends on the ride height your after and the tire height. I know you can fit 20's in the rear, but ride and tire height I think will play a factor on the fronts.

I just found this pic. I'm not sure but these look like 20's to me...

By no means is it a Donk... Not exactly my thing but with the right ride height it might work.