Bill
it is unlikely you did any damage with dexron. Many i have talked with say that dexron is actually closer to type a(original eq.) than type f. However, like harry, i have used type f for 30 years. It is thicker, and to me, on a classic car thicker is better. Last summer, driving home from the nationals, (100 degrees) my car car overheated and puked it's fluid. I installed an aftermarket trans cooler to help with the problem in the future. Good luck.
Bill