Need help assessing this 1965 Dodge Dart 270 4-dr sedan

Congrats on your a body. For tire the first thing I'd look for are 14 inch rims. Goes a long way in the future and improves handling. You have to buy the tires anyways. Take a ride to your nearest junkyard. Also plan on spending $1,000 - $2500 more before you get in good running cond. Find a good garage that works on old cars. Have them pull the wheels and ck the brakes and brake lines then have them change the trans fluid and adj the bands. Hopefully there is a drain on the convertor and check the adjustment on the kickdown lever. Also it would be a GREAT idea to have them swap over to a dual master cly. (a major safety issue). These things also have mechanical camshafts. So have them do a tune up (points/plugs) and adj. the valves set timing at 12 btdc. Also have them put a wrench on everything as you never know what's been changed on old cars. I'm sorry for all the work but this will at least get you a very good start. PS make sure the battery is always up to charge. And most important HAVE FUN.
If you're not worried about keeping it stock, I'd consider doing a big bolt pattern disc brake conversion and get some 15" wheels for it. I just had a 225/70/14 tire go bad and had to order it. Just had to wait a day, but 14" tires are getting phased out too it seems. If you're going to keep the stock 13" wheels, take a look on the Discount Tire website.