The 706 Vortec heads are even slightly superior to the commonly found 862 heads. The reason is that the 706 heads are SPM (semi-permanent mold) made, while the 862 heads are sand-cast. The SPM ...

Note that the Vortec Gen III and Gen IV overlap in some ... and the Gen IV have 243/799 heads. The 862/706 heads have smaller combustion chambers than the Gen IV, raising the compression ratio ...

In 1996, Chevrolet added Vortec heads to their 5.0L and 5.7L V-8 engines. This top end makeover also brought a redesigned fuel delivery system known as a Central Sequential Fuel Injection (CSFI ...