In this study, the improvement of neutronic performance of a dual purpose modified PACER concept has been investigated. Flibe as the main constituent are fixed as 92% coolant. ThF4 is mixed with increased mole-fractions of RG-PuF4 starting by 0 mol % up to 1 mol %. TBR variations for all the investigated salts with respect to the RG-PuF4 contents are computed. Tritium self-sufficiency is provided with the ThF4 when the adding RG-PuF4 content is higher than 0.75%. The energy multiplication of the blanket is increased as 70% with adding RG-PuF4 contents to ThF4. High quality fissile isotope U-233 are produced with increasing RG-PuF4. DPA and helium production increases with increased RG-PuF4 content in molten salt. Radiation damage with dpa < 1.7 and He < 3.3 ppm after a plant operation period of 30 years will be well below the damage limit values.