Cloyes S390T Engine Timing Camshaft Sprocket

Cloyes Timing Camshaft Sprocket S390T

The Cloyes S390T timing camshaft sprocket is built for engine timing service on a wide range of Chevrolet and GMC V8 applications, including classic Camaro, El Camino, C10, K10, Blazer, and Corvette models. It is a specific-fit metal sprocket with precision-machined dimensions for accurate timing system service.

Key Features

• Brand: Cloyes Timing Camshaft Sprocket
• Part number: S390T
• Metal construction with gray finish
• 36-tooth design for single-row timing chain applications
• Helical tooth form for quieter operation
• Precision-machined bore for true fit
• Specific fit, not universal
• Three mounting holes with 0.34" inside diameter each
• Inside diameter: 0.75"; outside diameter: 5.70"; thickness: 0.52"

Product Details

Cloyes timing gears and sprockets are engineered for engine rebuilds and routine timing service where accurate chain engagement matters. The S390T is CAD designed and manufactured with advanced materials, then tested for function and durability to support dependable timing performance. Cloyes also notes that when replacing the timing chain, the tensioner, sprocket, and guide components should be inspected and replaced together as part of a complete timing system service.

This part cross-references 340235 for the same application. It is a direct-fit timing camshaft sprocket for many Chevrolet and GMC truck, van, and passenger car platforms, including Chevrolet C10, K10, Camaro, and GMC Jimmy applications listed in the fitment data.

Common Problems This Part Can Address

• Worn or damaged camshaft sprocket teeth
• Timing chain noise caused by sprocket wear
• Incorrect cam timing from a fatigued timing gear
• Fitment issues during engine rebuilds with worn original components
• Timing system service on high-mileage Chevrolet and GMC engines

Installation Notes and Tips

Verify engine application details before installation, especially on listings marked without balance shaft or with standard duty engine. This sprocket is specific fit and should be matched to the correct timing chain system, tensioner, and guide setup. For best results, inspect the full timing set during service and confirm bore, tooth count, and mounting-hole alignment before assembly.

Quality Assurance

Cloyes manufactures this timing camshaft sprocket using CAD-based design, advanced materials, and durability testing to support consistent engine timing performance. The S390T is built for dependable service in rebuild and replacement applications across many Chevrolet and GMC platforms.