Trivia: How much did the 440 option cost for a 1968 Roadrunner?

Unless someone can prove differently, my research indicates-

The 440+6 was available mid year 1969, and again for 1970 and 1971.
Starting in 1972, a 440+4 was available, but if ordered, the RR became a GTX.
This continued for 1973 and 74.

Except for the Superbird (which WAS available with a 440+4, 440+6, or Hemi, but NOT a 383), those are the only optional 440 engines for the Road Runner I am aware of.

Now someone swapping a 440 INTO a RR was and is VERY COMMON, and if it is then sold, a lot of times the new owner thinks it's factory and doesn't know any better, or how to tell.