Not getting any backfires, it was running on this exact distributer and timing not more than a month ago. No more cats. I haven’t touched the tune since it was running and starting great every time. Now I can get it to start once or twice and then it won’t start and both times I can get it to start it will just die on its own. We have good fuel pressure, carb is rebuilt and cleaned. I’m not sure what’s going on.