Help me get this CB450 Idling

So I recently got a 1974 CB450. I have tried a 2 sets of coils, both used. Spark seems decent. I have adjusted the timing according to Bills method and also check a with a timing light. The time looks great, the advance is going a little to far. But the problem I seem to have is idling and popping. I have gone through the carbs twice and the jets look clean. The bike will idle if I leave the choke closed just fine with no back fire. If I open the choke it will rev up and then die usaully if I let it down below 2000 RPM. Also it backfires at low RPM.

Also I drove around a little and it seems to loose power at about 45mph then will either come back or if I let off gas it might reset and come back a little.

Also I have adjusted the valves according to shop manual.

I have made new gaskets for the carb intake boots, so I think I eliminated any leaks there.

Help any suggestion.

I am gonna try and pick up a new set of coils and wires tomorrow. Will these make a difference if they are a higher Ohm rating on the coils?

Thanks

Ben