Auto Parts Prodigy Rochester 2GC 2‑Barrel Carburetor for Chevy 350/400 — Large Base (3 11/16" x 2 1/16") with Hot‑Air Choke

Direct-fit replacement Rochester 2GC large-base carburetor for Chevy 5.7L (350) and 6.6L (400) small-block V8s with an automatic hot-air choke. This turnkey carburetor from Auto Parts Prodigy is built to reintroduce dependable, factory-style performance to classic Chevy trucks and muscle cars from the 1970–1980 era. Engineered as the Large Base Rochester 2GC, it arrives pre-set for smooth idling and easy starting, includes a mounting gasket and fuel filter, and is intended to solve common OEM carburetor symptoms such as hard starting, rough idle, and hesitation under acceleration.

How do I confirm this carburetor fits my intake manifold?

Measure your existing carburetor mounting bolt pattern before ordering. This listing is for the Large Base Rochester 2GC with a mounting bolt spacing of 3 11/16" x 2 1/16"; the Small Base version uses a different footprint.

• Measure center-to-center bolt distances on your intake flange.
• Large Base required if your pattern is 3 11/16" x 2 1/16".
• If your manifold measures 3 1/4" x 1 7/8", choose the Small Base instead.
• Not compatible with 4.3L V6 S10 applications.

What starting and idle features are included?

This carb features an integral hot-air choke assembly with a thermostatic coil inside the round black housing for reliable cold starts. A vacuum pull-off port helps prevent carburetor flooding as the engine warms, and idle mixture screws are factory pre-set for convenience.

• Automatic hot-air choke connects to stove tube heat for consistent cold starts.
• Vacuum choke pull-off port reduces bogging after startup.
• Idle mixture screws adjustable to tune for elevation or fuel variations.
• Pre-calibrated jets aimed at typical 350/400 small-block configurations.

Will this restore throttle response and solve drivability issues?

Yes — this Rochester 2GC is designed to replace worn or leaky OEM two-jet carburetors and eliminate common drivability complaints. Replacing an old unit with a properly sized, pre-set carb can noticeably reduce flat spots, surging, and erratic idle behavior when installed correctly.

• Replaces aging, leaking two-jet Rochester carburetors.
• Improves throttle transition and mid-range acceleration response.
• Addresses hard-starting and unstable idle symptoms frequently seen on vintage Chevy V8s.
• Maintains factory-style performance without requiring major engine modifications.

What does the package include and what should I prepare for installation?

The kit ships with the Large Base 2GC carburetor, a matching mounting-base gasket, and a new fuel filter pre-installed for immediate installation. Basic hand tools and a clean intake surface are all you need to complete the swap; you may want to have a torque wrench and some thread-safe sealant handy.

• Included: Large Base Rochester 2GC carb, mounting base gasket, pre-installed fuel filter.
• Recommended: inspect vacuum lines, replace fuel hoses, and clean intake flange.
• Idle mixture and minor jet tuning possible to accommodate altitude or fuel octane.
• Not supplied: linkage clips for non-standard throttle setups or special conversion adapters.

Who is this for? This Rochester 2GC Large Base carburetor is aimed at owners of 1970–1980 Chevy and GMC trucks and muscle cars with small-block 5.7L (350) or 6.6L (400) V8 engines who want an authentic, reliable replacement that preserves stock drivability. It's appropriate for restorations, daily drivers, and weekend cruisers that require a direct-fit, hot-air choke-equipped unit; however, verify your bolt pattern and engine application before purchasing to ensure a correct fit.

FAQ

Q: Does this carburetor fit my Chevy 350 or 400 V8?

A: Yes—if your intake bolt pattern measures 3 11/16" x 2 1/16". Measure the manifold before ordering to confirm Large Base fit.

Q: Is the choke automatic and will it improve cold starts?

A: Yes. It has an automatic hot-air choke with a thermostatic coil designed to use stove tube heat for easier cold starts.