Moroso 20404 Stroker Steel Oil Pan w/Sump Tray for Chevy Big Block Mark IV 8 In

Vehicle Fitment

• Chevrolet Big Block Mark IV (396, 402, 427, 454) - fits most GM chassis with two-piece rear main seal
• Compatible with most GM A-body, B-body, and full-size chassis applications using Mark IV BBC engines

Fitment Notes

• Designed for Mark IV style Big Block Chevy engines only - does not fit Gen V or Gen VI BBC blocks.
• Does not fit 1962-1967 Chevy II with V8 engine.
• Does not fit V8 Vega or V8 Monza.
• Does not fit 1955-1957 Tri-Five Chevrolet models.
• Some chassis may require crossmember modification - verify ground clearance before installation.
• Recommended oil pump pickup: Moroso No. 24440 (fits Moroso BBC Race Pumps Nos. 22149, 22150, 22159, 22160, 22162, or M77/M77HV style pump).
• Uses stock dipstick location.

Features

• Stroker-clearanced design accepts up to 4.25-inch stroke with steel rods and 4.090-inch stroke with aluminum rods.
• Integrated trap door and anti-slosh baffle maintain consistent oil coverage at the pickup under acceleration and deceleration.
• Flat-sided sump design provides increased header clearance, reducing fitment conflicts with aftermarket exhaust.
• Internal sump tray included for additional oil control and reduced aeration.
• 8-inch deep rear sump increases oil capacity over stock without sacrificing ground clearance.
• Black powder coat finish for corrosion resistance and clean appearance.
• Compatible with most starter and flywheel combinations.
• Uses standard two-piece rear main seal block configuration.

Specifications

• Part Number: 20404
• Material: Steel, Black Powder Coat
• Sump Style: Wet Sump, Rear T-Sump with Internal Sump Tray
• Pan Depth: 8 inches
• Sump Length: 10 inches
• Oil Capacity: 7 quarts (not including filter)
• Max Stroke (Steel Rods): 4.25 inches
• Max Stroke (Aluminum Rods): 4.090 inches
• Rear Main Seal Style: Two-piece
• Engine Application: Chevrolet Big Block Mark IV (two-piece rear main seal)
• Drain Plug Thread Size: 1/2-20
• Recommended Pickup: Moroso No. 24440

Included Components

• 1x Moroso 20404 Steel Stroker Oil Pan
• 1x Internal Sump Tray

Product Description

The Moroso 20404 is a stroker-clearanced steel oil pan built for Mark IV Big Block Chevy engines running two-piece rear main seals. The 8-inch deep, 10-inch long rear T-sump holds 7 quarts and accommodates crankshaft strokes up to 4.25 inches with steel rods or 4.090 inches with aluminum rods - making it well-suited for built and stroked BBC applications. An integrated trap door and anti-slosh baffle keep oil at the pickup through hard acceleration and deceleration, while the included internal sump tray further controls oil movement and reduces aeration.

A key distinguishing feature of the 20404 is its flat-sided sump design, which increases clearance between the pan and exhaust headers - a practical advantage on builds where aftermarket long-tube headers are installed. The black powder coat finish provides durable corrosion resistance. The pan fits most GM chassis running Mark IV BBC engines but does not fit 1962-1967 Chevy II V8, V8 Vega/Monza, 1955-1957 Tri-Five Chevrolet, or Gen V/VI blocks. Some installations may require minor crossmember modification; verify ground clearance before ordering. Use Moroso pickup No. 24440 for proper fitment with BBC race-style oil pumps.