The carburator for the V-6 was a Stromburg two barrel. I don't remember the model, the 6066 pages have all the info on them plus setting a V-6 up with the correct manifold for a 4 barrel Holley. The 6 in your pickup is a 305 CID and could be an E model, our 64 had an e and our 61 two ton has a 305 C, I don't know if letter changes accured in these years or not the C was for the big trucks at that time.
