These pads are located on B and RB blocks. Most people know this but information about your engine can be located on these pads.
G383 is stamped on this 383 making G represent 1971 So this engine was built in probably late 70 for the 71 year model.
The 440 stamp pad is located in a different area of the block as noted in the video.
![](https://i.ytimg.com/vi/LWx36ABK4sU/maxresdefault.jpg)