There are a handful of 5. V8 engines in the Vortec family, and they are broken into two categories: Gen III and Gen IV. As a rule, Gen III is the superior plant. Buyers should be more wary of the Gen IV model. While the 5. L Vortec V8 has proven itself as Chevy’s longest-lasting engine, it isn’t the only engine in Chevy’s lineup that simply refuses to call it quits. Two other legendary Chevy engines that deserve a shout are the 6L Vortec V8 and the 6. L Duramax Diesel V8.