I dropped a '76 440 into my '66 Newport with minimal issues,modify exhaust,etc...I still have to get the B&M flexplate for the '67 727...car is perfectly drivable I guess at least for now but there is a noticable vibration.
For my car it is a mix of all sorts of parts...I think I have a '74 radiator...a '67 383 clutch fan...modified brackets for alignment of belts,'67 rear end,'68 gas tank,changed to '68 dual res.drum brake master cylinder and about a million other things.
I did buy a reman. points distributor at Pep Boys for easy drop in and go on the car.Never have drove the car much but haven't had any problems with the points or the mismatched components other than the needed flexplate.