Diesel engines, for all their rugged usefulness, can be tremendously polluting. They produce more NOx — nitrogen oxides-based emissions – than gasoline-fed cars, as well as more particulates, aka soot ...

Earlier this year we bolted a cam and headers on a 5.3L Gen III called Little Bro and made 458 hp at a screaming 6,600 rpm. That engine revealed the potential of a lesser-known family of iron-block GM ...