Originally Posted by NANKET
Originally Posted by AndyF
The books I have don't go back that far so it could be a 1961. R would be 1961 but I haven't seen the M before nor have I seen the serial number on the ID pad. But that is an early block casting so it does make sense that it is a 1961 engine.


No, not if you know these early engines, then it makes sense you don’t know what you are typing. I know you wrote a book, but not on early year 413 block stampings.

A 1961 will have R41 with the 3 missing. Then the month and day like on a 440 block.

15 years in the 300 club taught me these things.


Wow, my memory must still be pretty good. I had a '61 413 in the late 1980s and I remembered the R41 (somebody was asking on another site a few weeks ago). Mine also had HP stamped on it (or whatever signified high perf at the time). Couldn't even get the guy 15 miles away with the 300G to come look at it and make me an offer (.030 over, no ring ridge) and he didn't have a motor for his car.