I ‘grew up’ eating tacos on the streets of TJ in the early 2000s so my preferred tacos are al pastor, tripas, and adding to that later in life, real suadero. I don’t get the “TJ-style” with a huge glop of guacamole — I never saw that back then; we used to love how the taqueros would ‘throw’ the spoonful of thin salsa onto the tacos from a couple feet away. I also don’t get the birria craze — birria used to be a Sunday morning thing where you get a container from the street and some tortillas and take it home, not eaten like the current quesabirrias you see everywhere now. Also it was goat.
So I’m probably not the best to recommend cabeza or birria (although I do order lengua every now and then) in SF, which isn’t the best taco town, although you can find good tacos.
Taqueria Vallarta is probably the closest to a certain type of street taco you’ll find in Mexico cooked on a sombrero style cooker. Not sure if they have cabeza but I always get their buche there which is pretty good.
El Gallo Giro gets a lot of love online but even giving it multiple chances, can’t say I care for it. I’d rather go to Taqueria San Jose even (which has cabeza but I’ve never had it).
There are two new actual street taco spots that we randomly found (after walking to Mission Bar to eat Yamo — they were/are doing takeout only) on Mission at night. We had just gotten back from living in PDC for a couple months so can’t compare but they were pretty good. And looks like they have cabeza.
That’s a lot just to say I’m not the best help on your SF cabeza taco quest. But here are some photos to maybe inspire you for some other tacos from some recent taco eatings/crawls (we do a mission taco crawl every month or so we’re in SF).
Pastor and buche from Vallarta
New (?) street tacos on Mission: El Pollito
Al pastor from Taqueria San Jose
Pastor from Ojo de Agua (across the street from 850 Bryant)
Not SF, but just had al pastor and lengua from the Tacos la Perla truck in West Oakland last week (lengua was good)
Also not SF, but al pastor from El Ultimo Baile in Oakland (definitely bring home some of the great flour tortillas he sells too)