I don't think the Zeeker Head was the original Indy Head. The Zeeker Heads were available back in the early to mid 80's. They were a pretty good head in the Day. I knew a couple people that had a set.
I had a friend that was going 8.10's with a 477 ci 2300lb altered with Zeeker heads and tunnel Ram. This was back in 1989 - 1990.
He ended up getting one of the first sets of Indy Heads and Tunnel Ram back in 90 or 91. I don't recall any ties between Indy and Zeeker.
Although I could be wrong.