Running a 285-40-18 in the rear. I like the 27" tall height on this tire and it's a pretty common size so you can find them reasonably priced.
Running a 245-40-18 in the front. It's 25.5 tall and a little narrow for the wheel. I'm thinking about going to a 255-40-18 that's about 26" tall and a bit wider when I get new tires. I just wasn't sure if they would fit, however now after trying the 245's, I'm pretty confident they will fit.
Rather than experimenting with new tires on a build like this Dart. I hit up the tire shops and buy used for the initial fitting. I'm into the 4 used tires mounted and balanced for $160.00. Now that I'm getting the bugs worked out of the car and starting to enjoy driving it. I'm thinking about buying a nice new set of tires.
Best advice I could give anyone going to big wheels is to get the tallest tire you can find front and back. Most of the big wheel tires are in the 25" tall range and they look a little weird on these old cars. Also try and find a common size tire that comes on a Porsche, Corvette, or other high performance car they are usually cheaper and likely to be made longer.
