R6 440 block?

Like this? Apparently..the 440 I bought isn’t just any old 440...it’s a 1972 R6 440 that somehow found its way into a 1975 Chrysler New Yorker.
It kind of explains all the peculiar characteristics I found as I was disassembling the engine..none of the info and pics I was seeing looked like what I had on the engine stand.

Can anybody tell me more about this R6 block I have?

After I saw NASCAR in the description I figured Yea fkn right..
But..it’s got all the described markings of an R6 block...right down to the year
No.

look at the front of the engine, near where the timing cover would go, there will be an R number there.