FBO's black HEI ignition box

I‘m not sure which box he was talking about when he said it doesn’t retard with RPM.

Like I said, they ALL retard with RPM. How much and when it starts are variables.

Thats why you need to test for it.

I was there when Don started talking about building his own ignition boxes. I said it was a waste of time. I still say that.
Rat, I have been running one of Don's white boxes for three years.
It has performed very well, no issues, and I really like the rev limiter.