I assume you are talking "Amateur-Built".
You won't find chapter and verse in the FARs because the part that covers that is part 43 which does not apply to experimentals. However, your operating limitations state that "An experimental aircraft builder certificated as a repairman for this aircraft under part 65.104, or an appropriately rated FAA certificated mechanic may perform the condition inspection required by these operating limitations." Note that it says "mechanic" not inspector. Therefore IA is not required. The IA is typically required on type certificated aircraft to assure the the aircraft meets it's type certificate. An experimental amateur-built has no type certificate.