I am ready to being the project on my Cougar. I’ve been told by many that I’m am making a mistake by not leaving it stock. Its a base model 289 car that’s in very good condition. I am the second owner, it has 92k on it. My question is not what the car is worth, but the Engine and Trans. with anything and everything under the hood included. I’ve decided to put a stroker motor in the car. Originally I was going to keep the Engine and Trans in case I decided to put it back to OE. Depending what its worth will determine my decision. Its still in the car now and runs perfect. any thoughts? Thanks. Andrew
What year and engine code is it? A '67 A-code might be one to keep stock, but a '67 or '68 C- or F-code not so much. For the latter, a stroker upgrade with manual transmission conversion would probably increase its value.
I can’t answer your question on what it’s worth. But I’d go with the stroker motor if thats what you really want to do. If your going to put your money and time into it anyway. A base model 289 is probably not worth straying away from what you really want to do to the car. Unless origionality is what you really want. Im actually going to drop a stroker 408 into my car someday… someday 
But chances are restoring to origional won’t be worth as much as you hoped by not being a GTE or Eliminator or XR7-G etc… I think catvert68 is right. Stroker will most likely increase value.
If you never plan to sell it then do what you want anyway. Wether it’s worth more or not you won’t be happy until you do with it what you truely want to do. Hope that helps. Good luck.