You need to know what top rpm you can realistic expect to get from your engine per your engine builder or experience.
Then make your best guess and from what you might learn from others put a best effort gear on.
If you hit your expected rpm take gear off until it will normally fall below what you expect.
Then put just enough gear back on to again hit your expected rpm.
And your all set with the only thing left being to set your clutch to engage as near as you can to peak torque.
If you have to fudge peak torque engagement up or down it's usually better to put engagement a small amount above peak torque.
If you put it below you'll lug your engine on the starts.
Last but most important is if you cannot hit your expected high rpm even with a ton more gear then you need, you have other issues to fix first.
If you have that problem when you fix an issue you'll find your rpm will go up.
Keep fixing stuff until you can get your rpm up probably taking gear off in the process.
Once your satisfied your at maximum rpm reliably the you start taking even more gear off so you can go faster.
With experience you will hit a point where your just as fast as others and then it becomes very fine tuning to gain even a fraction of a tenth.
At that point you'll either be the front runner or be running with them consistantly
It doesn't matter what engine you use I think the above thought process will be correct.
That is until you get to having so much hp as in a 410 sprint car that even without a clutch you can spin the wheels at low speed most all of the time.
At that point even if your in a 410 it will be about your driver learning how to not apply hp to go faster.
In your low hp arena it's about free the thing up with the grip of the track to the minimum needed and maintain momentum.
When you get to the top of your game be it a predator or a 410 it becomes a game of driver skill maintaining momentum.
If you were flying a plane it would be maintain thy momentum less the ground come up and smite thee.
With an oval racer it's maintain thy momentum less the wall come down and smite thee. ...
edit: The only difference in the process is between how long it takes someone new to go thru the process and how long it takes experienced racers.
Top racers are able to look at a track knowing their equipment and put what's needed now on the track.
It takes longer depending on your experience and don't worry or fret about it everyone goes thru the same process.