I'll try to answer what I can. I don't remember many blown 409's in this era. A fan......if ran was a rarity although it would be doable. What you may find in Google searches are "retro rods" recreating a combination I don't remember competing in the sixties. Blown motors in this era (64-66) were small block Chevys, Olds (very popular), 392 Hemis. Fords were pretty much not in the picture. The 409 was a carbed motor more often found in stockers than in upper classes of drag racing. Of course this was an era of experimentation as drag racing truly was in its infancy. By '66, BBCs were becoming more common but were far from common. Blown Chrysler wedges might be in the gas class. Late model hemis were just barely being used in the top classes. Take your window to '68 and Hemis and BBCs were much more common in the gasser ranks. Legal gassers had to have a stock production frame in '64. By '66, I believe replica frames were allowed if they were made of square or rectangular tubing. Most were built of rectangular tubing. Round tubing was not legal for an NHRA legal gasser in this time period......I don't know if or when NHRA accepted round tubing. One other thing to remember AHRA and circuits were alternatives to the Wally show. I think that front wheel wells were optional although I'm pretty sure rear wheel wells were required. Oh yes remember headlights. I hope this helps.