Hi, Ike, how are you?
If you don't mind here's my 2 cents as to what I know. Others on this site have infinately more knowledge than I do about these great cars.
A while back there was such a debate as to whether or not a '70 R/T could come from the factory with a 340 engine.
At least as far as what I see in a '70 Challenger brochure, the 340 was "N.A." for the R/T car.
Here's a pic from stockmopar.com. I left it big to see the writing.
Like CP said, stranger things have happened on the assembly line.
Does your VIN have a "S" (R/T) or an "H" (base) as the second digit?
There was a code A66 Challenger 340 option that made a regular Challenger look like an R/T
Not to argue what you have but this is just what I've seen in the literature. You very well may have a '70 R/T 340. Do you have a build sheet or any other paperwork?
Hope this was helpful. Again, not to argue but more very curious.
Take care!
