straight from the original owner's mouth, the 440 came with a 7-year, 70,000-mile powertrain warranty, while the Hemi had a 90-day, 4,000-mile warranty.

well, in addition to the price, that right there seems to explain why only about, what was it, 9 or 11 thousand 426 hemis were ever sold from 65 to 72

https://moparconnectionmagazine.com/twice-in-a-lifetime-charlie-ryers-1969-dodge-coronet-r-t/