Holman Moody made a huge amount of changes to the car for entry into the Monte Carlo Rally of 1964, but the Falcon needed to remain looking as an OEM production car.
Ford had to comply with minimum production of 1000 Rallye Sprint cars so they offered an actual 1964 Falcon Rallye Sprint for 1964 (RPO) which included all of the Holman Moody parts that were fitted to the 1964 Monte Carlo Falcon Race cars. In turn these cars were actually classed as a Regular Production Option vehicle to meet the criteria for entry into the 1964 Monte Carlo Rally.
I recently managed to find an original 1964 Falcon Rallye Sprint hand book.
What a find! all of the original part numbers too!