This is going to sound odd. I put in this replacement engine a while back, and had some photos when it first arrived at the shop. Sure enough, it has the distributor cap markings 5 4 6 we have been talking about. I don't see distributor cap markings on earlier distributors. When the shop put in the engine, they put in a new distributor, but it was the old style with the 4 5 3 configuration. I guess it can run on either one, as it has been running fine since installation, 23 mpg, smooth running. I think I will buy one of the newer distributors that has the 5 4 6 markings on the distributor cap, install it, and see what happens.