I found myself in the same situation about 5 years ago. Ever since I bought my 5.0L Jag XKR about 6 years ago, I was never driving the Pantera. It was just too much of a pain in the ass. I'd always have a problem starting it, I couldn't drive it in Los Angeles traffic and heat without the worry (and the actuality) of overheating, the seats were lousy, and with my XKR, it was considerably quicker, very luxurious, I didn't have to think about any external conditions, and was much more manageable on the track as well. So, I also thought about selling my '72. Instead, and mostly because of my emotional attachment to its beauty, I decided that I was going to make it into a car that was more user friendly. And for the past four years, it has been changed to accomplish this. Gone is the finicky carb, installed is fuel injection. I already had a Fluidyne radiator but added higher capacity fans. Tore out the entire interior, installed C-4 seats swathed in leather with diamond quilted stitching, covered the entire interior the same way including the dash. We replaced the non original motor with a potent, built 500hp Cleveland, installed harnesses for the completely non-functioning seat belts, installed flush windshield glass for a more svelte look. Resprayed the already good paint with a high quality paint job, tidied up the suspension, fixed the exhaust leaks and installed a new exhaust system. And I have just gotten the car back a couple of weeks ago. I haven't had the time to take it out on "real" drives yet, but am aching again to do so after many years of just not wanting to bother.
So my advice to you would be to isolate the reasons for your thinking and either work to make it what you want or sell it and have peace of mind. Good luck with your decision.
