Wiseco PTS531AS Pro Tru Street Chrysler 440 Forged Piston Set 4.320 in. Bore

The Wiseco PTS531AS is a Pro Tru Street forged piston set designed for Chrysler 440 big-block engines with a 4.320-inch bore. Built to stock compression height specifications (2.050 in. compression height), this set is engineered to deliver reliable street performance with the strength and precision of a forged piston — bridging the gap between OEM replacement durability and race-proven construction.

Wiseco's Pro Tru Street series pistons are forged from high-strength aluminum alloy, offering superior strength and dimensional stability compared to cast pistons. The flat-top design maintains factory compression ratios while supporting increased power output from mild performance builds. Each piston is precision CNC-machined to tight tolerances for consistent fitment and optimal ring seal.

Key Features:

• Application: Chrysler 440 big-block engines
• Bore Size: 4.320 inches
• Compression Height: 2.050 inches
• Base Piston PN: 5034AS
• Construction: Forged high-strength aluminum alloy
• Series: Pro Tru Street — built to stock dimensions for direct replacement with performance upgrade
• Set Includes: 8 pistons (complete engine set)
• Precision CNC-machined for consistent tolerances and optimized ring groove fitment
• Compatible with Wiseco replacement ring sets for easy future servicing

The Pro Tru Street line from Wiseco — a manufacturer with over 80 years of piston-making heritage — is an ideal upgrade for enthusiasts rebuilding Chrysler 440 engines who want the reliability of forged internals without moving away from stock displacement or compression targets.