You can NOT time an engine, any engine by ear. That is a no no from the go go (could be a rap song in there....I claim all rights to it but I can't rap) and as suggested you need a timing light and learn how to use it.
I happened to grow up knowing one of the best Comp racers in the country. He was a FORD by but by had loads of talent so I forgave the Ford issues. Anyway, I was 15 and we stopped by his place to shoot some bulls and race the benches around. I'll never forget that day. He told me 90% of the people at a drag strip don't understand how to time an engine or use a timing light. That was 1978-79. He was absolutely correct.
Sadly, after all this time, it's still true. This ain't a rip on any one. Just stating what I've learned. Fortunately, time has passes and things like the grid and EFI have come along to help. But, if you can't grasp carb function or how and ignition system works, IDK that a computer makes it better.
Ramble off, waiting for AJ to come along and make my post more interesting.