is this possible?  

That is a very good question.  One I'm trying to research myself.  I just purchased a 68 4 door and since the interior is totally shot, I was considering changing the car to a 2 door.  I'm a larger man and the two door would be MUCH easier to get in and out of.
I figured the experts on here would know without any doubt if there are any compatibility issues.  Some cars have a longer wheelbase between the 2 and 4 door models.  Does anyone know if they're different?  I'm only finding one measurement.
Thanks in advance,
Kori
Proud owner of a 72 Dodge Challenger and now a 68 Dodge Dart