Haytalras 300-123 GM LS1 LS2 LS6 Cathedral Port 102mm Hi-Ram EFI Intake Manifold 5.7L 6.0L

300-123 102mm Hi-Ram EFI Intake Manifold for Cathedral Port LS

A Hi-Ram EFI intake manifold with a large 102mm throttle body opening for GM LS1, LS2 and LS6 engines with cathedral port heads (5.7L / 6.0L, standard deck). Built for big-cube, high-rev race engines where hood height isn’t a limitation.

• Long runners with an as-cast tapered cross-section that works across many engine combinations
• Longitudinal plenum top
• Fuel rails machined for -8 AN O-ring fittings, sized for high fuel flow
• 102mm throttle body opening; 12.32 in. tall

Fitment

LS1, LS2 and LS6 engines (5.7L / 6.0L) with cathedral port heads, in original applications and LS swaps. Full specifications are in the Specifications tab.

What’s Included

• 1 × Hi-Ram intake manifold
• 1 × fuel rail kit
• Additional parts as shown in the product photos

Why Haytalras

• Built in our own factory. We cast and CNC-machine our intake manifolds in-house. The same factory has produced intake manifolds for Holley, TSP and Professional Products.
• Checked before it ships. Every manifold goes through air-tightness, dimensional and visual inspection.
• Ships from the US. Free shipping from our California and Georgia warehouses, out the door within 24 hours, usually delivered in 3–7 days.
• Backed by us. 30-day free returns and a 1-year warranty on casting defects.

Frequently Asked Questions

300-122 or 300-123: what’s the difference?

The throttle body opening. The 300-122 takes a 92mm throttle body; the 300-123 takes a larger 102mm unit for engines that need more airflow.

Will it fit under my stock hood?

In most vehicles, no. At 12.32 in. tall, plan on a cowl hood or hood modification.

Not sure it fits?

Email haytalras@gmail.com with your engine code and cylinder head casting number and we’ll confirm before you order.