Poll: Which Car to Take

[Skippy]

I'm planning a trip back east to visit family. It will be approximately 2600 miles each way. All three of my cars are physically capable of making the trip, but none are ideal. I'd like some help deciding which one to take.

The contenders:

'83 300D-Highest mileage, but also the newest, the most comfortable on the highway, and in the best overall shape.

Plus:

1. 3.07 rear end for quiet and efficient highway operation.
2. Cruises easily at 80+ mph while still getting well over 20 mpg.
3. Best seats.

Minus:

1. Transmission front seal leak. About one quart in 400 miles. I picked up some stop leak today but haven't put it in yet.
2. ACC is wonky. Blower works as directed. Heat sometimes works great, sometimes not so much.
3. High performance summer tires could spell trouble if I don't pick routes carefully and monitor road conditions.

'71 250-Lowest (apparent) mileage, but also pushing 40 years old. Transmission freshly rebuilt and working well, but the car was down for about a year and I've only recently started driving it again. I made a big loop from Carson to Reno, down to Fallon, and then back to Carson in it today. No major issues, so I think it'll be okay on reliability.

Plus:

1. At least as fast as the 300D. Cruises easily at 80+ miles per hour.
2. Better seats than the 240, but not quite as good as the 300.
3. Michelin all-season tires have the best chance of doing well in the snow.

Minus:

1. Gets around 15 mpg while cruising easily at 80+.
2. Noisy at highway speeds.
3. Is old enough that parts availability in the event of a breakdown may be considerably worse than with the 123's.
4. Blower no worky.

'77 240D-I've driven this one back and forth to San Diego several times, most recently this New Year's Eve. It always makes it without an issue (except that one tire that broke a belt), but is slow.

Plus:

1. Proven long-drive reliability.
2. Fuel economy nearly as good as the 300.
3. Best heater of all the cars.

Minus:

1. Slow. Slow like a semi. Slow like, well, like a 240D. Maintaining 75 mph is a struggle, and some grades get me down into the 40's in third gear.
2. Deteriorated driver seat gets uncomfortable on long drives.
3. Noisy at highway speeds, but not quite as much as the 250.

Get a Rental-More expensive than driving any of my own cars, but the vehicle would most likely be a new or newish Mercury Grand Marquis. Thanks to modern technology, they offer 450 SEL performance, roominess, and ride while getting 300SD fuel economy. I have not priced this option yet.