Installed both flaps on the wings and trimmed the inboard top skins to clear the fuselage.
With the flaps trailing edge aligned to the neutral aileron there is a +/- 1/2" gap between the fuselage bottom skin and the trailing edge of the flap.
A quick search on VAF revealed that this is a common issue on the RV-8. The third image shows how Randy Lervold (www.rv-8.com) solved this problem and we'll probably do the same.