Filling stock 2F in 1986 FJ60 after restoration. I got enough concentrated prestone to make the required 17.4qts. Was planning on 50/50 dilution unless someone recommends otherwise. I probably cant put the entire amount in the radiator fill opening. Whats the best way to fill an engine with coolant thats been out of the truck for a while. It is back in the truck and all hooked up.