what doe replacing the 292 engine with a 312 do to the value

Hi RedFox ... My general impression is that the car in it's original condition and trim will have more collectors value, but I don't know the ebbs, flows, and biases of the T-Bird market. These guys should however. Visit the Thurderbird Ranch at http://www.tbirdranch.com/ and look for contact info at the bottom of the page. These guys should be able to give an educated answer to your query ... Good luck!

Here is a site to tell you the value of your car: http://manheimgold.com/car_lo.html Your car is in excellent condition so according to the Gold Book would go for $57,000. With the increased horsepower you could get more than what it cost you for the new engine. However, the person who is buying the car may want it in its original state, but I cannot imagine that more horsepower would be bad. The additional value of the car with the added horsepower would depend on who is buying it, but definitely add cost and time of the new engine.