LS Intake Port Identification

The shape of the intake ports on Generation 3 and Generation 4 LS-based engines vary significantly. Generation 3 heads feature a "cathedral" port, while most Generation 4 heads utilize a "rectangle" port. The primary difference is the volume of air (CFM) the heads can flow, which determines how much power they can support. For proper performance, the intake manifold port shape must match the cylinder head port shape. This can be accomplished by using our intake to cylinder head adapters that can be used to combine any cylinder head to any intake or supercharger, including LT Gen V.

The LS7 and some LSX heads are unique, since they feature a "raised" port and a different bolt pattern, making them non-interchangeable with standard Gen 3 or Gen 4 components. The bolt holes on LS7 and LSX heads are positioned higher than those on standard LS3 or LS1 heads.

What this means to you?

We receive many calls asking if an LS7 intake will bolt onto LS3 heads because of a "killer deal" found online. Unfortunately, it will not fit due to different bolt hole locations and port shapes. Always verify your head port shape before purchasing an intake unless you plan on adapting it. We manufacture a full line of intake adapters in our Kansas machine shop.

See link to shop Intake Manifold Adapters