Thanks so much to the CHs that posted about these trucks- quite a few years ago. We were so lucky to read the brief report of a former Californian who really knows his/her tacos.
The Michoacan truck , yellow w/ red awning- near the Northernmost end of trucks- was our mecca.
Carne Asada and Albondigas (marinated grilled pork)
were 'as good as it gets'. On Friday, the woman comes and makes sopes and gorditas (a thick masa cake, fried, split and stuffed) and boy, they were heaven-sent. They offer a long list of taco fillings, including lots of offal, and Tortas, quesadillas, burritos, etc. Prices are ridiculously low ($1.50 taco) and they do not stint on the filling. You can also help yourself to sauteed onions, roasted peppers, and beans. The 3 different sauces were all too hot for me, and we found the tacos to have enough flavor on their own.( I urged them to raise their prices to $2.50 tacos) On both Thurs and Fri. we saw that their customers were about 70% latinos and 30% office workers and truck drivers. Parking was easy and plentiful.
There are picnic tables along the water-side park but it was hot so we ate in our car. The nearby 'fish tacos' truck uses tilapia so we avoided that. But the puerto rican truck next to the Michoacan one- had very good fried beef empanadas (BIG, $2.50) and fried beef -filled potato croquettes. The truck guys were as nice as could be and my only complaint is that it is REALLY messy food when you eat it from their ridiculously flimsy paper plates. You are much better off bringing some black plastic rounds w/ clear lids (which we just happen to travel with!) like restaurants often give you.
Google Map even lists the trucks and gives good directions for getting there (~ 8 minutes from Chapel St. in New Haven.) On our next visit from Boston to New Haven- we'll see if any of the other trucks serve non-tilapia fried fish tacos.