<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: njsteve</div><div class="ubbcode-body">The numbers photo you supplied is the engine assembly date info. The 1970 and 1971 engines were cast in 1969 and then assembled shortly thereafter. They were then stored away til orders came in to match them up with a car. April 17 of 1969 is not 13 days earlier. It is a year and 13 days - if your car built in April/May of 1970.
Here is a photo of my old 1971 hemicuda ragtops assembly info - it was built a little more than a year before the car in 1970 for a May, 1971 car.
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Steve,
Adding/adjusting your info, on this pad on Hemi blocks, the date that looks like a date is the date the block was machined, or something like that. This date on your old ragtop’s block was 4-20-70. Most Warranty Hemi blocks will also have this date stamp. And you’re right that these machined blocks got stockpiled. But all the other markings on both your block and on Phil’s will only be on blocks assembled for production use, and these other markings do show the date the engine was fully assembled. The "G" on your block designates ’71 usage, while Phil’s "F" designates ’70 usage. Along with this letter these production blocks also got the “MN426xxx” number (or in most ’71 examples “NM426xxx”, with the first 2 digits reversed). As Phil mentions the 4 digits after MN426 are the 10K date code stamping, showing exactly when the block was assembled. In the case of your yellow ragtop, your NM number shows that its block was assembled on ‘3570’, which is Friday, May 7, 1971. I looked up the Scheduled Production Date for you old car and it was scheduled for build on 519 (May 19, 1971). So your car’s block was fully assembled 12 days before your car was scheduled to be built.
- Wade