I've been hitting Modesto fairly often the last couple of months making my way around town. Generally, my exit takes me through Downtown and over the train tracks. There is a semi-permanent set-up of taco trucks and pop-up tents at the intersection of H Street and 8th Street.
I tried 3 trucks one night, Los Portolitos, El Super Taco 2, and F.K. Jessica's. Of the three, Los Portolitos was the best that evening. Jessica's had the longest line, probably a good 10 people waiting on orders. I ate one al pastor taco at all three locations. (Los Portolito's al pastor taco pic)
Jessica's, the truck with the longest line, had al pastor that seemed more like ground and seasoned pork rather than meaty chunks and frankly, pretty wet. El Super, was fine, just nothing special. Los Portolitos was far and away the best in my 15 minute eating extravaganza. The individual pieces of meat were well seasoned and had a good mix of fat and meat.
However, earlier in the day, I made a quick stop at the Chevron Station at the Kansas Ave. Exit on Highway 99 for a taco at El Maguey (the taco you see with the radishes). Now that was a good al pastor taco. The balance was right, the meat was tasty, the condiments were fresh.
All the tacos I ate that day were $1.00. Long live tacos!