ZL-1 heads w/o exhaust heat crossover passages ?

[Rock Crusher]

I am new to this site and seek your expert opinions...

I have a set of ZL-1 heads # 3946074. The casting dates are 2.18.69 and 4.21.69. These heads appear to have been cast without exhaust heat crossover passages. They are the only #3946074 heads that I have seen without them, although I read an article on the Camaro Research Group site that says that ZL-1 heads do not have this passage. www.camaros.org/copo.shtml

The heads have several logos, letters and numbers stamped on the ends- Batten Heads, Romulas, Michigan (stylized logo) Diamond Elkins (std individually hand stamped letters) E 892 R is stamped on one head and E 892 is on the other (I assume that R signifies right side) They also have 71201 and H.C. stamped on both heads. I read some where that H.C. was stamped by the factory and signifies high compression ? I can post photos of these features if needed.

They have been decked and ported. I know about C.J. Batten and Butch Elkins and their extensive port and flow research with ZL-1 heads. Unfortunately, both appear to be out of the business, so I can't ask them personally. I would like to find out more about these heads and determine if they have any historical racing provenance. If anyone knows how or where I can find out that sort of info, I would greatly appreciate it.

Thanks in advance.