409 hi-po heads

[RPOLS3]

Originally Posted by tom406

Hi Jake-quick question on the date codes. Since these heads were cast with the Julian date codes of DEC 12 and DEC 17 (non leap year http://www.348-409.com/numbers/hdc.html ), are you having to extrapolate that they’re 1962 heads since production of 690 heads apparently ended Nov 12 1963? That makes sense, but I’m wondering if there’s any way to tell ‘62 and ‘63 castings apart if the Julian numbers were, say, October dates instead. GLWS

My assumption is they are 1963 model year production heads (dated late 1962). My understanding is that anything prior to late 1961 castings (for 1962 model year production) have an actual calendar date vs. the Julian date. If I am incorrect or someone has better or more accurate information please let me know and I can update the posting.

Thank you.