Here's something interesting. What it means, I don't know.
When I brought my WC home it too would make your eyes burn. 460 with Edelbrock 750cfm. I worked on it off and on and have gotten it much better by leaning it up some. Edlebrock was involved and got some good advice from them. Here's where it gets interesting. A good friend who tunes engines by ear helped me in retuning the ignition. He advanced the timing until detonation and back off. Then he shut off the motor and then a restart. If the timing is too far advanced it will difficult to start. For these several minutes until he got the timing where it needed to be, we had those god awful eye burning fumes again.
For whatever that's worth.