Cy,
It was too late in the day to contact ACA but I spoke Barbara (I can't remember the nice lady's name already) at API. She was told by Jerry Melhoff, Jr. that he amended drawing 3-486 to state the API tail wheel model 6131 was an acceptable alternative. She said today the very same thing that she mentioned when I called a few years back, that Melhoff felt that only amnedment to the drawing was needed, I presume because of the FAA regs
I'm sending this note to API along with the email address for the CAR 4A reference
The paragraph appears on page 14. I'll order the drawing for ACA which shows the update tomorrow. I was told today that API has been producing these tailwheels now for 40 years.
Carl Prather