What is your bore size?
Normally aspirated or boosted?
Nitrous oxide?
Injected alky or gas carb, etc?
RPM and HP targets?

For a healthy gas carb bracket race engine, I moved to the camp that says:

Top 0.0045" per inch of bore (.0050" in higher hp applications)
2nd 0.0055" per inch of bore

ie for a 4.375" bore, 0.021" and 0.024"
For a milder build, slightly less is OK.