These production Vortec heads were used in the new Vortec 350ci engine intended for -, -, and 1-ton Chevy pickups. Amazingly, this mundane, production-based 1.94/1.50-inch valve head performed ...

Scoggin-Dickey made this rotating display stand to visibly illustrate the differences between Vortec heads and conventional small-block Chevy heads, such as these used by 1985-92 TPI applications.

As you'll see, the Vortec heads combination was worth barely 378 hp, and the top five small-block Chevy heads we tested would easily push the Chevelle into the mid-12s without much difficulty. See ...

GM's 706 Vortec heads are the cheapest and most effective heads you can use on your 4.8-liter and 5.3-liter, and even some 6.0-liter LS engine builds. Bold statement? Well, not really.

As an example, if the valve seat on a small-block Chevy iron head is 2.02-inches then 90 percent of that would be 1.818 inches (2.02 x 0.90 = 1.818). It’s very easy to increase the diameter of ...