Wiseco PTS539A45 AMC 360 Pro Tru Street Forged Flat Top Piston Set 4.125 Bore

The Wiseco PTS539A45 is a complete Pro Tru Street series forged flat top piston set designed for the AMC 360 V8 engine. Built for street performance and high-output engine builds, these pistons are forged from 4032 aluminum alloy and machined to precise tolerances at Wiseco's facility in Mentor, Ohio. This set features a .045 over bore size of 4.125 inches with a flat top, -8.6cc dish design that delivers a compression ratio of approximately 10.57:1 with a 58cc combustion chamber or 11.67:1 with a 50cc chamber.

Key Features:

• Forged 4032 aluminum construction for superior strength and reduced weight versus cast pistons
• ArmorGlide skirt coating for reduced friction, quieter operation, and extended piston life
• Oversized, symmetrical radiused valve pockets accommodate high-lift camshafts and oversized valves
• Chromium alloy steel piston pins with Spirolox retention included
• Compatible with both floating and pressed pin type connecting rods
• Thicker decks and performance-optimized piston ring lands for durability under high-output conditions

Specifications:

• Bore: 4.125 in. (.045 over)
• Compression Height: 1.590 in.
• Stroke: 3.440 in.
• Rod Length: 5.875 in.
• Pin Diameter: 0.930 in.
• Dome Volume: -8.6cc (flat top)
• Compression Ratio: 10.57:1 @ 58cc / 11.67:1 @ 50cc
• Replacement Ring Set: S100S8-4125-5
• Replacement Single Piston: 5539A45

What's Included: 8 forged pistons, 8 piston pins, pin lock rings (Spirolox), and a premium plasma moly piston ring set — everything needed for a complete engine rebuild.