ARP 8740 Chromoly Main Stud Kit | 4A-GE / 4A-GZE (AE86 Corolla / AW11 MR2 / AE92 Corolla)

ARP 8740 Chromoly Main Stud Kit

For 1983–1987 Toyota Corolla AE86, 1984–1989 Toyota MR2 AW11, and 1987–1991 Toyota Corolla AE92 coupe equipped with 4A-GE / 4A-GZE 16V engines.

Overview

The ARP Main Stud Kit is a high-strength bottom-end fastener upgrade for Toyota 4A-GE DOHC 16-valve and 4A-GZE engines. It covers the 1983–1987 JDM Corolla AE86, 1985–1987 U.S.-Market Corolla Sport GT-S, 1984–1989 Toyota MR2 and 1987–1991 JDM Toyota Corolla AE92 coupes and 1988–1991 U.S.-Market Corolla GT-S AE92 coupe applications. It replaces the factory main-cap bolts with precision-manufactured studs designed to provide more consistent main-bearing-cap clamping during engine assembly.

The studs are manufactured from heat-treated 8740 chromoly steel with a black oxide finish and a tensile-strength rating of 200,000 psi. Hardened washers and high-strength hex nuts are included to complete the main-cap fastening system.

Key Features

• Designed for Toyota 4A-GE DOHC 16V and 4A-GZE engines
• Performance replacement for factory main-cap bolts
• 8740 chromoly steel construction
• 200,000 psi tensile-strength rating
• Heat-treated fastener construction
• Precision thread-rolled stud design
• Black oxide finish
• Provides consistent main-bearing-cap clamping
• Helps reduce main-cap movement and fretting wear.
• Includes hardened parallel-ground washers and high-strength nuts

Main Stud Design

The stud-style fastening system separates block-thread engagement from final clamping torque. The studs, nuts and washers form a complete main-cap fastening system.

This arrangement reduces the twisting load placed on the fastener during final tightening and helps maintain more consistent clamping across the main-bearing caps. It is well suited to 4A-GE engine rebuilds, naturally aspirated performance builds, and other applications where increased bottom-end fastener strength is desired.

Vehicle Fitment

Toyota Corolla — AE86

• 1983–1987: Trueno (JDM) / 4A-GE / 4A-GEU 16V.
• 1983–1987: Levin (JDM) / 4A-GE / 4A-GEU 16V.
• 1985–1987: GT-S (U.S.-Market) / 4A-GE 16V.

Toyota MR2 — AW11 / MK1

• 1984–1989: JDM / naturally aspirated 4A-GE 16V.
• 1985–1989: U.S.-Market / naturally aspirated 4A-GE 16V.
• 1986–1989: JDM Supercharged / 4A-GZE.
• 1988–1989: U.S.-Market Supercharged / 4A-GZE.

Toyota Corolla / Sprinter — AE92 — Coupe

• 1987–1991: Corolla Levin / Sprinter Trueno (JDM) / 4A-GE 16V
• 1987–1991: Corolla Levin / Sprinter Trueno GT-Z (JDM) / 4A-GZE
• 1988–1991: GT-S coupe (U.S.-Market) / 4A-GE 16V.

For the original 4A-GE 16V / 4A-GZE two-bolt main-cap configuration. Not for windage-tray mounting. Main-bearing bore correction may be required when changing fasteners. Aftermarket caps and reinforcement ladders require their own hardware selection. Engine-swapped vehicles require the supported engine and main-cap arrangement.

Fitment Notes

• For Toyota 4A-GE DOHC 16-valve and 4A-GZE engines
• Engine-swapped vehicles require the same supported engine and main-cap interface; chassis identity alone does not establish fitment.
• Designed for a 2-bolt main-cap configuration
• Not designed for windage-tray mounting

Product Specifications

Brand: ARP
Product Type: Engine Main Stud Kit
Engine Family: Toyota 4A-GE / 4A-GZE
Engine Displacement: 1.6L
Cylinder Head Configuration: DOHC 16V
Main Configuration: 2-Bolt Main
Fastener Style: Stud
Nut Style: Standard Hex
Material: 8740 Chromoly Steel
Finish: Black Oxide
Tensile Strength: 200,000 psi
Washers Included: Yes
Nuts Included: Yes
Windage Tray Provision: No
Application: Crankshaft Main Bearing Cap Fastening
Manufacturer Type: Aftermarket Performance

Should You Choose Main Bolts or Main Studs?

ARP Main Stud Kit — Best for a performance build that calls for more consistent main-cap clamping

Choose studs when your engine-building plan specifies a stud-style fastening system for the original main caps. They are not an automatic upgrade requirement for every street engine, and changing fasteners may require main-bearing bore correction.

ARP Main Bearing Cap Bolt Kit — Best for keeping a planned rebuild more affordable when studs are not required

The bolt kit retains the bolt-style arrangement at a lower price point. Neither kit is automatically compatible with aftermarket caps or reinforcement ladders.

Our Recommendation: Keep sound factory fasteners for a normal rebuild unless the engine-building plan requires an upgrade. Choose bolts for a lower-cost bolt-style upgrade, or these studs when the build specifically calls for their clamping arrangement.

What's Included

• (10) ARP main studs
• (10) High-strength hex fastening nuts
• (10) Hardened parallel-ground washers
• ARP Ultra-Torque fastener assembly lubricant