Well I am running 225/70/14's and I believe I have 3.55's for gearing. My goal is to make my Dart a highly functional yet very fun to drive street machine. That means I plan to actually use it for forty mile round trip commutes about three times a week. Keep in mind this will be in Southern California freeways so I need to cruise comfortably at 70/75MPH. I have a mild 318 with a 260H with an edelbrock carb and intake combo.
As for funds I am by no means a blue blooded high roller. I'm thinking in the range of two grand or so for this project. However if more money is needed to do this right I'll just have to save longer.
Thanks for the response. With the 3.55's i think your good with the OD. Your engine is fairly mild and that's actually a plus because the rpm drop won't effect performance like it would in a high strung small block. I've been around the 200R4 in several cars and it's a good trans, although a adapter would have to be used. A Mopar OD may be a little more cost effective but either way i think your budget is easily obtainable. One plus is you don't need a super strong trans, so just a good rebuild with some decent clutches will suffice. Good luck on what ever you choose and kudos for driving it as much as possible.