Sierra Starter Mounting Bolt Kit 18-8402-1, Replaces 50-806963A4, Fits Chevy 4.3L/5.7L Alpha/Bravo Starters

The Sierra 18-8402-1 is a starter mounting bolt kit for the Sierra 18-8402 permanent magnet I/O starter, a permanent magnet, 11 tooth starter built for GM-based sterndrive engines. The kit supplies the two bolts used to secure that starter to the engine block: one 18-8402 bolt and one 18-8404 bolt. These are the correct replacement fasteners when the original mounting bolts are lost, damaged, or corroded during a starter swap.

This bolt kit is matched to starters fitting Chevy engines with 12 3/4 inch flywheels using a straight across bolt pattern, and is specified for 4.3LX/LXH Alpha/Bravo 262 CID engines (SN OF803000AN through OF803114AN) and 5.7L Alpha (EFI)/5.7L Bravo (EFI) engines (SN 355305AN/22560AN). Using the correct mounting bolts ensures the starter seats and aligns properly against the flywheel housing, maintaining the straight across bolt pattern required for these applications.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-8402-1
• Product Type: Starter Mounting Bolt Kit
• Kit Contents: One 18-8402 bolt and one 18-8404 bolt
• Bolt Pattern: Straight across
• Weight: 0.17 pounds
• Country of Origin: China

Fitment

• Chevy engines with 12 3/4 inch flywheels
• 4.3LX/LXH Alpha/Bravo 262 CID, SN OF803000AN/OF803114AN
• 5.7L Alpha (EFI)/5.7L Bravo (EFI), SN 355305AN/22560AN

Replaces (OEM)

• 50-806963A4
• 50-806965A2
• 50-806965A4

Frequently Asked Questions

What does the Sierra 18-8402-1 bolt kit include? The 18-8402-1 kit includes one 18-8402 bolt and one 18-8404 bolt, the two mounting bolts used to secure a Sierra 18-8402 starter to the engine.

What starter is the 18-8402-1 bolt kit designed for? This bolt kit is designed for the Sierra 18-8402 permanent magnet I/O starter, an 11 tooth starter for GM-based sterndrive engines.

Which engines does the 18-8402-1 fit? It fits Chevy engines with 12 3/4 inch flywheels, specifically 4.3LX/LXH Alpha/Bravo 262 CID engines (SN OF803000AN/OF803114AN) and 5.7L Alpha (EFI)/5.7L Bravo (EFI) engines (SN 355305AN/22560AN).

What bolt pattern does this kit use? The 18-8402-1 mounting bolts are set up for a straight across bolt pattern, matching the mounting configuration of the corresponding starter.

Does 18-8402-1 replace OEM starter mounting bolts? Yes, the 18-8402-1 kit is a cross-reference replacement for OEM numbers 50-806963A4, 50-806965A2, and 50-806965A4.

How much does the 18-8402-1 bolt kit weigh? The Sierra 18-8402-1 bolt kit weighs 0.17 pounds.

Is the 18-8402-1 a genuine Sierra part? Yes, 18-8402-1 is the Sierra manufacturer part number for this starter mounting bolt kit, not a generic aftermarket substitute.

Do I need both bolts in the 18-8402-1 kit to mount the starter? Yes, the starter mount uses both fasteners together: the 18-8402 bolt and the 18-8404 bolt included in the 18-8402-1 kit.

Where is the 18-8402-1 bolt kit manufactured? The Sierra 18-8402-1 starter bolt kit is manufactured in China.

Will the 18-8402-1 bolts fit a starter without a 12 3/4 inch flywheel? No, the 18-8402-1 bolt kit is specified for Chevy engines with 12 3/4 inch flywheels using a straight across bolt pattern; it is not listed as fitting other flywheel sizes.