Im Lvl87 in HC where should I farm for runes and gear?

I have almost no mf but i can clear everything on p1-3.

Should I focus on farming only TZ? Always use the shards and farm all acts?! Or just run chaos sanc, cows?

Tyvm

( I play echoing strikes, eth cv insight-vipermagi-spirit budget gear )

Hello , technically speaking every mob can drop high rune in hell. But i'm used to farm chaos sanctuary because is easy to reach even without enigma, easy clear and good density. in 26 years of diablo i found only 2 bers , and it was yesterday and the day before yesterday. Both of them in chaos sanctuary. Also cows is usally a nice spot to farm rune/bases to trade