What would be considerd the "general rule of thumb" when it comes to casting dates versus build dates for a 1970 model year 440? Has anyone seen a block that was cast 5-6 months before the actual SPD of the vehicle?

I seem to remember that The Mopar Action Gurus believed that the casting dates should usually preceed the Car by no more than 2 months and often no less than 2 weeks. There were exceptions though I guess.

The major exception would have been during "changeover" (June, July, August) when the foundries were still producing but car production was held off for the new model usually introduced in September. I know because I was there.

I am looking at a car that is reported to be all matching numbers, but I am double checking casting dates versus assy dates.
Thanks for the answers guys.

I have seen several 70 440 HP blocks that were cast 3-4 months ahead of the engine assembly date. My 3/5/70 SPD 70 GTX has a block cast date of November 1969....the exhaust manifolds & water pump housing were also from November. I would not be surprised to see even wider spreads in cast dates versus assembly dates.