Tomei MLS Head Gasket – Toyota 2JZ-GTE | 87.5mm Bore | 1.2mm Compressed Thickness | TA4070-TY03D

Tomei’s multi-layer steel (MLS) head gasket for the Toyota 2JZ-GTE — 87.5mm bore, 1.2mm compressed thickness. Engineered for high-boost turbo builds where cylinder pressure demands exceed what a composite gasket can reliably seal. Made in Japan. A critical sealing component for any serious 2JZ-GTE rebuild.

Bore and Thickness — Confirming Correct Specification

Two dimensions must be confirmed before ordering:

• Bore Diameter — 87.5mm: The stock 2JZ-GTE bore is 86mm. This gasket is for engines bored to 87.5mm — a +0.75mm per side overbore, a common first overbore specification on a 2JZ-GTE rebuild running aftermarket oversized pistons. This is not a stock bore gasket — confirm your actual cylinder bore diameter before ordering. Using a gasket with a bore smaller than the cylinder bore will cause the gasket to overhang into the combustion chamber and fail. Tomei also makes this gasket in 86mm bore for stock bore applications
• Compressed Thickness — 1.2mm: Compressed thickness (CT) directly affects compression ratio — thinner gasket = smaller combustion chamber volume = higher effective compression ratio. At 1.2mm, this is on the thinner end of Tomei’s 2JZ-GTE gasket range, resulting in a slightly higher compression ratio compared to the 1.6mm variant. On a high-boost 2JZ-GTE build where lower compression is typically desired for detonation management, confirm that 1.2mm CT is correct for your target compression ratio and boost level. Tomei also offers this gasket in 1.6mm CT for builds targeting lower compression. Calculate the effect of gasket thickness on your compression ratio before ordering

MLS Construction for the 2JZ-GTE

The 2JZ-GTE in a high-boost application generates cylinder pressures far beyond OEM specification — peak cylinder pressure under high boost scales directly with boost level and compression ratio. The factory 2JZ-GTE uses a composite head gasket rated for OEM cylinder pressures. At elevated boost levels, composite gaskets are not rated for the peak pressure at each combustion event and will fail over time through progressive combustion gas leakage.

Tomei’s MLS gasket uses multiple layers of embossed stainless steel — two outer facing layers with precision-stamped sealing beads and a solid centre layer. Under head bolt clamping load, the beads compress and create a series of high-pressure sealing rings around each combustion chamber, coolant passage, and oil passage. Under heat and pressure cycling, the MLS layers flex with the head and block rather than crushing permanently — maintaining consistent clamping load and sealing force through repeated thermal cycles. For a 2JZ-GTE build running elevated boost on pump fuel or E85, MLS is the correct and only appropriate gasket specification.

Key Features

• Multi-Layer Steel (MLS): Stainless steel multi-layer construction — engineered for sustained high cylinder pressure. Do not use sealant on MLS gaskets — install dry
• 87.5mm Bore: For 2JZ-GTE engines bored to 87.5mm with matching oversized pistons — not for stock 86mm bore engines
• 1.2mm Compressed Thickness: Thinner MLS option — results in slightly higher compression ratio than the 1.6mm variant. Verify against your target compression ratio and boost level before ordering
• Made in Japan: Manufactured by Tomei at their Japanese facility
• Tomei: A respected Japanese performance engine components manufacturer with extensive 2JZ-GTE application experience — their products are used in serious Supra and Aristo build applications globally

Installation Requirements

• MLS gaskets require a deck surface finish of Ra 50 μin (1.27 μm) or better on both the cylinder head and block mating surfaces — confirm surface finish before installation. A rough or improperly finished deck will not allow the MLS sealing beads to seat correctly
• Install dry — no sealant. MLS gaskets must not have sealant applied to any surface
• ARP head studs are strongly recommended — consistent clamping load across all head studs is critical for MLS gasket sealing integrity under high boost
• Follow Tomei’s published torque specification and torque sequence exactly
• Torque in multiple steps to final specification
• Check piston-to-valve clearance after final assembly

Fitment

• Toyota Supra JZA80 (1993–2002) — 2JZ-GTE
• Toyota Aristo JZS147 (1991–1997) — 2JZ-GTE
• Toyota Aristo JZS161 (1997–2004) — 2JZ-GTE

87.5mm bore — not for stock 86mm bore engines. Confirm cylinder bore diameter before ordering. Confirm compressed thickness (1.2mm) against your target compression ratio and boost level — Tomei also offers this gasket in 1.6mm CT. MLS gaskets require Ra 50 μin (1.27 μm) or better deck surface finish on head and block. Install dry — no sealant. ARP head studs strongly recommended. Professional installation by a qualified engine machinist is required.

Specifications

• Brand: Tomei
• Part Number: TA4070-TY03D
• Construction: Multi-Layer Steel (MLS) — stainless steel
• Engine: Toyota 2JZ-GTE
• Bore Diameter: 87.5mm (overbore — not stock 86mm)
• Compressed Thickness: 1.2mm
• Origin: Made in Japan
• Application: JZA80 Supra / JZS147 / JZS161 Aristo — 2JZ-GTE