BMW Toyota B58 Head Stud Thread Insert Kit

The BMW Toyota B58 Head Stud Thread Insert Kit provides your machine shop everything needed to repair or upgrade the engine block threads on BMW Toyota B58 engines. Designed for precision and durability, this kit allows you to restore damaged threads or prepare the block for oversized head studs for improved clamping strength.

Each BMW Toyota B58 Head Stud Thread Insert Kit includes:

• (1) Specialized drill bit for proper thread preparation
• (1) High Speed Steel 3-Flute Tap
• (1) High Speed Steel Extended 3-Flute Tap
• (14) Precision stainless-steel thread inserts
• Red threadlocker

Available in 11mm for OEM-spec head stud thread repair or 12mm for use with our Oversized Head Stud Kit, this thread insert kit ensures a secure and permanent repair capable of withstanding extreme cylinder pressure and torque loads.

How these inserts work:

Our insert design supports the use of both factory head bolts and high-quality aftermarket ARP head studs. These fasteners use rolled threads, which are up to 20% stronger than cut threads, and are engineered to flex and return to shape as the engine heats and cools—maintaining consistent clamping pressure on the head gasket throughout every heat cycle.

Benefits of Installing Oversized Head Studs:

1. Repair Worn or Damaged Threads
   When an engine block’s head bolt holes become stripped or elongated from repeated torque cycles or overheating, a standard-size stud may no longer hold properly.
    
   By drilling and re-tapping the holes to a larger diameter and using oversized studs, you restore proper thread engagement and strength—often stronger than original.
   
   
2. Increase Clamping Force
   Oversized studs can have a larger shank diameter, which increases tensile strength and reduces stretch under high cylinder pressures. This is particularly beneficial for high-boost turbo where combustion pressures are extreme.
   
   
3. Reduce Head Gasket Failure
   Stronger or larger studs provide more uniform clamping across the cylinder head, which improves gasket sealing and minimizes the risk of head lift or gasket blowout.

Not all engine blocks are suitable for oversize head stud installation. Due to differences in casting thickness, core shift, and material distribution, some blocks may not have enough surrounding material to be safely machined for larger fasteners.

A skilled and experienced machinist must inspect the block and be confident in its integrity before performing any machining. Improper assessment or installation may result in cracking, coolant passage intrusion, or structural failure. All modifications are performed at the installer’s own risk.

Please Note: Installing oversized head studs requires precise machining; drilling and tapping the block must be completely straight and to the correct depth.

Don't have a machine shop capable of the job? Send your block to 5150 for our oversized head stud installation service.

BMW B58 Gen 1 Applications:

1 Series

2016-2019     F20/F21     M140i

2 Series

2016-2019     F22/F23     M240i

3 Series

2015-2019     F30/F31     340i / 340i xDrive
2016-2019     F34     340i GT / 340i GT xDrive

4 Series

2016-2020     F32/F33/F36     440i / 440i xDrive

5 Series

2016-2019     G30/G31     540i / 540i xDrive

6 Series

2017-2019     G32     640i GT / 640i GT xDrive

7 Series

2015-2019     G11/G12     740i / 740i xDrive

X3 Series

2017-2019     G01     X3 M40i

X4 Series

2018-2019     G02     X4 M40i

BMW B58 Gen 2 Applications:

3 Series

2019-Present     G20/G21     M340i / M340i xDrive

4 Series

2020-Present     G22/G23/G26     M440i / M440i xDrive

Z Series

2019-Present     G29     Z4 M40i

5 Series

2020-Present     G30/G31 LCI     540i / 540i xDrive

6 Series

2020-Present     G32 LCI     640i GT / GT 640i xDrive 

7 Series

2019-Present     G11/G12 LCI     740i / 740i xDrive

X3 Series

2020-Present     G01     X3 M40i

X4 Series

2020-Present     G02     X4 M40i

X5 Series

2018-Present     G05     X5 xDrive40i

X6 Series

2019-Present     G06     X6 xDrive40i

X7 Series

2018-Present     G07     X7 xDrive40i

ALPINA B58 Gen 2 Applications:

B3 Series

2020-Present     G20/G21     B3

B4 Series

2022-Present     G22     B4

B5 Series

2020-Present     G30     B5

XB7 Series

2020-Present     G07     XB7

Toyota B58 Gen 2 Applications:

A90 / A91 Supra

2020-Present     GR Supra 3.0    
2020-Present     GR Supra 3.0 Premium    
2021-Present     GR Supra 3.0 A91 Edition