I own a 66 charger with 361 engine. how rare are these engines? that were put into these cars.

I think the only way to find a value on this car is to have it appraised. The 361 engine used the same stroke 3.38 but a smaller bore 4.125 compared to the 4.25 bore on the 383 engine. Also the compression is lower @ 9:1 which is the same as the 318. Not sure on popularity and how many are out there. I would talk to an appraisler (spelling could be wrong). Good luck.