More than likely(from experience) it's the direct clutch first then O/D clutches, as long as the converter has the same pressure as the clutch packs it will always hold more power, it has too as it has twice the surface area. I thought my stock transmission's converter was slipping as I could flash the RPM's in lockup, on the tear down the direct clutches were slipping, O/D were gone and the steels were blue... ... converter was fine when they opened it up!
Jim