Most internal combustion engines rely on motor oil for one reason: lubrication. The oil gets pressurized between 10-70 psi and spends most of its life subjected to roughly 200 degrees’ worth of heat.

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 ...