Are these Denver/Cheater Heads? ID help.

[Jason in TX]

Swap meet find yesterday. I believe these might be Cheater heads, but not sure. What do I have here? Notice that the top one's water neck is machined down a little bit, and the bottom one's neck is smooth.




Both have the same part number. I saw on the internet that the 6049 was the left side, and the 6050 was the right side. Which side carries both part numbers???




The top head in the picture below looks unaltered. The bottom head has been milled (compared to the top one) and the area over the valves opened up. I was told by an old stock car racer once that they would make them pull the heads to show that they weren't modified, so they would only mill one to increase performance a little bit, but have the stock one to pull and show the officials.




They both have a little "C" in a circle, similar to the "copyright" symbol. Again, "cheater?" or "canada"




And one says 79 in the top left corner...



and one says 140 in the top left corner...




The 140 head has the smooth water neck, but is the head that is milled.

The 79 head has the stepped, or machined water neck, but is not milled.