Probably. But the best way to know is to get a good magnifier and check the trichomes. You can get a really nice 60-120x hand microscope on Amazon for $12.
Your percentage of old pistils on the main tops tells me it's almost ready. The trichome method isn't necessary and it shouldn't be your only go to indicator. I like to judge the plant as a whole. How many and where it's putting out new pistils still is one of the best indicators IMO. A plant that is near done will have hardly any new white pistils near the top especially on the main buds.