Product Overview
Forever Fabrication has developed the Vortec 3500/3700 Turbo Manifold as a purpose-built solution for turbocharging applications on the Vortec 3500 and 3700 (commonly referred to as the 3.5L and 3.7L) inline-5 engines from General Motors' Atlas family. This log-style manifold is engineered to support high-performance turbo setups while prioritizing durability, precise fitment, and reliable construction. It draws from the manufacturer's proven design philosophy, incorporating refinements based on experience with related platforms such as the Vortec 4200.
The manifold is hand-built in the United States and is currently available for pre-order, with production batches planned to meet demand.
Key Features and Construction
The manifold is constructed using Schedule 10 stainless steel cast piping, selected for its exceptional strength and resistance to the thermal and mechanical stresses associated with turbocharged operation. Each unit undergoes TIG welding with back-purging to ensure high-quality welds that maximize structural integrity, flow characteristics, and long-term reliability.
A log-style design is employed, which balances packaging constraints with acceptable exhaust flow for most boosted applications. While log manifolds inherently provide less optimal flow distribution compared to tubular headers, this configuration delivers solid performance within the practical limits of the design.
An optional wastegate provision is available, featuring a pre-welded pipe and V-band flange compatible with the TiAL MVR 44mm and Turbosmart GenV HyperGate 45mm wastegates (noting that both flanges share identical dimensions). This option facilitates external boost control without requiring additional fabrication by the end user.
Compatibility and Intended Use
This manifold is specifically designed for turbocharged setups on Vortec 3700 inline-5 engines, with compatibility extending to the closely related Vortec 3500 variants. It supports common aftermarket turbo configurations, as demonstrated in product imagery featuring components such as the VSR 67/66 billet turbo from VS Racing.
The product is explicitly intended for off-road and motorsports use only. It is not compliant with California Air Resources Board (CARB) standards and is not legal for installation on emissions-controlled vehicles in California or other jurisdictions adhering to CARB regulations. Purchasers must confirm that the manifold will be used solely in race or off-road environments.
This manifold forms part of Forever Fabrication's growing lineup of platform-specific components for the GM Atlas engine family, including related items such as stainless steel manifold flanges and exhaust hardware.
For those pursuing a reliable, domestically produced turbo manifold solution tailored to the Vortec 3500/3700 platform, this product offers a compelling combination of thoughtful engineering and robust construction.
Get in Touch with Forever Fabrication
Whether you're looking for custom metal fabrication, welding services, or have a specific project in mind, we’re here to help. Fill out the form below, and a member of our team will get back to you shortly with a quote or to discuss your project. For a quicker response, give us a call at 651-894-2210. We look forward to working with you!