F.Y.I. I drained my radiator and it held 6.5 quarts exactly what my owner manual says it should. Now this is radiator only!!! You still have extra coolant 50/50 mix in the block and heater core.
I decided to do the radiator replacement only with Zerex G-05 (H.O.A.T. approved) and distilled water. I bought 1 gallon of 100% and mixed it 50/50 with distilled water. Now I have extra coolant to top it off as needed. I used the fill air valve (in the fill neck) and it worked as designed. No air in the system and temperature is normal.
I plan on replacing just the radiator coolant as I did this time about every 18-24 months. This should suffice and I'm happy with the way I did it. Works for me!!!!
Have a great week!!!!