I live in a chevy town in montana. I have talked to several people and haven't been able to find the timing for a ford 400 with a milwalkee 351 cam. I had the engine rebuilt in july changeing it from a 2bl to 4bl. I had them put a performer edlebrock intake on and a 600cfm edlebrock carb.. I changed the primarys to 95s and the secondarys to 89. Hopeing for a leaner engagement of the four barrel. The only people that I could find that work on fords all set the timeing by ear. That isn't accurate enough for my truck. I tried advanceing it until it pings. I ran out of scale at 30 degrees before I got a ping. I then figured that the distributor must have some problems. I was also getting some flutter on the vaccume advance at about 45 mph. I change the distributor and think I stopped the flutter but I still don't have eny ping. Every one says that the ford 400 has a predetenation problem. Mine don't eny suggestions???

 

Detonation isn't always audible. Since you changed the jets you may not be able to hear it "ping" but detonation could still be occuring. My suggestion would be to try to find a facility with a chassis dyno and tune it that way. Otherwise you risk serious engine damage from extreme heat and mechanical stress due to detonation.