Hi,how can i find out what my 68 fastback 2+2 is really worth?

For a vehicle like this, the only way to get a good selling price is to check places like Old Car Trader, Hemmings Motor News, etc., for comps, or similar vehicles in similar condition. Old car values are very subjective and you will have to drop probably the top 2-3 prices you see, as a lot of times guys don't want to sell the car "unless they get top dollar" and so they may be overpriced. I would say it might be worth $15k to the right person.

I would suggest getting a professional in to appraise the vehicle.( try a local car club for help ) If you have modified it in any way from original , it will take away from the value of the vehicle . Big block cars tend to be worth more and also if it is a higher end model , such as a GT , or Shelby . I would guess the vehicle would be worth less than a #2 ( #1 being a showroom restored vehicle) especially if you have dome radical mods to the car .

You can also get a Marti-Report (google it) on your car. depending on how extensive of a report you want to pay for. You can find out all information about your car and how rare it might be, how many were built in your color with your options, etc. They can get very extensive and Marti might even have the original dealer invoice on your car. Any muscle car should have a copy of the report.