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Cylinder head nut & washer kit. Porsche 911 1978-89 - 99903109101K
99903109101K/KIT
Vehicle Group
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1978-1989 3.3L Turbo (930)
Information
Cylinder head nut & washer kit.
A complete fastening set of 24 cylinder head nuts and 24 head nut washers used to clamp the cylinder heads and cylinder barrels to the crankcase on classic air-cooled Porsche engines. This kit contains head nuts and "Large style washers"; used for 3.0 SC, 3.2 & 3.3 Turbo engines
Includes:
24 x 90110438204/1 - OE Match Cylinder head nuts
24 x 99903109101/1 - OE Match Head nut washers
Fits:
Porsche 911 1978 - 1989
Diagram ref no 16 and 17
This OE Match kit combines the correct-style M10 cylinder head nuts (OE ref no 90110438202) with the corresponding large head nut washers (OE ref no 99903109101). Together, they provide the correct bearing surface and clamping load distribution required during engine assembly or top-end rebuilds, helping maintain sealing integrity under heat cycling and high operating loads.
Head nuts and washers can suffer from corrosion, rounding, surface wear, and reduced load consistency after multiple rebuilds. Replacing them with OE-match hardware supports accurate torque application and helps maintain long-term clamp load stability - critical for top-end durability.
When to replace:
• During any top-end rebuild or head/cylinder removal
• Nuts show corrosion, damaged hex, or thread wear
• Washers are grooved, distorted, or heat-marked
• You suspect prior incorrect torqueing or hardware reuse history
• Preventive replacement on engines with unknown rebuild history
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99903109101K
The product you are viewing cross references to these numbers
A complete fastening set of 24 cylinder head nuts and 24 head nut washers used to clamp the cylinder heads and cylinder barrels to the crankcase on classic air-cooled Porsche engines. This kit contains head nuts and "Large style washers"; used for 3.0 SC, 3.2 & 3.3 Turbo engines
Includes:
24 x 90110438204/1 - OE Match Cylinder head nuts
24 x 99903109101/1 - OE Match Head nut washers
Fits:
Porsche 911 1978 - 1989
Diagram ref no 16 and 17
This OE Match kit combines the correct-style M10 cylinder head nuts (OE ref no 90110438202) with the corresponding large head nut washers (OE ref no 99903109101). Together, they provide the correct bearing surface and clamping load distribution required during engine assembly or top-end rebuilds, helping maintain sealing integrity under heat cycling and high operating loads.
Head nuts and washers can suffer from corrosion, rounding, surface wear, and reduced load consistency after multiple rebuilds. Replacing them with OE-match hardware supports accurate torque application and helps maintain long-term clamp load stability - critical for top-end durability.
When to replace:
• During any top-end rebuild or head/cylinder removal
• Nuts show corrosion, damaged hex, or thread wear
• Washers are grooved, distorted, or heat-marked
• You suspect prior incorrect torqueing or hardware reuse history
• Preventive replacement on engines with unknown rebuild history
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99903109101K
99903109101
90110438202
99903109101
90110438203
The product you are viewing cross references to these numbers
About kit
This kit is comprised of the following items:
24 x Cylinder head nut. Porsche 911 1965-89 / 356 / 912 (90110438204/1)
Unit Price: €2.80
InStock
24 x Head nut washer. Porsche 911 1978-89 (99903109101/1)
Unit Price: €3.51
InStock
Price: €151.44
In stock
Related products
Vehicle Group
- Porsche 924S 2.5L 1986-87
- Porsche 924S 2.5L 1988
- Porsche 944 2.5L 8V 1982-87
- Porsche 944S 2.5L 16V 1987-88
- Porsche 944 Turbo 2.5L 8V 1985-88
- Porsche 944 Turbo 2.5L 8V 1989-91
- Porsche 944 Turbo S 2.5L 8V 1988
Information
Engine head stud. Replace when doing engine overhaul work.
Require 10 per engine. Price is for each.
Fits
Porsche 924S 1986-88
Porsche 944
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
94410119700
The product you are viewing cross references to these numbers
Require 10 per engine. Price is for each.
Fits
Porsche 924S 1986-88
Porsche 944
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
94410119700
94410119700
The product you are viewing cross references to these numbers
Price: €12.61
In stock
Vehicle Group
- Porsche 924S 2.5L 1986-87
- Porsche 924S 2.5L 1988
- Porsche 944 2.5L 8V 1982-87
- Porsche 944S 2.5L 16V 1987-88
- Porsche 944 Turbo 2.5L 8V 1985-88
- Porsche 944 Turbo 2.5L 8V 1989-91
- Porsche 944 Turbo S 2.5L 8V 1988
Information
Engine Head Stud, SET OF 10
Fits
Porsche 924S 2.5L 1986-88
Porsche 944 2.5L M44.52
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
94410119700
The product you are viewing cross references to these numbers
Fits
Porsche 924S 2.5L 1986-88
Porsche 944 2.5L M44.52
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
94410119700
94410119700
The product you are viewing cross references to these numbers
Price: €313.76
In stock
Information
HEX HEAD BOLT M12X1,5X110MM (extra long)
This Item is an Original Porsche Part found by using our original Porsche Part Number Search. If you are ordering parts via this method it is your responsibility to make sure that you enter and purchase the correct products for your vehicle. Please only use the searched product if you are sure of the part numbers as parts cannot be returned if ordered incorrectly.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90008214201L
The product you are viewing cross references to these numbers
This Item is an Original Porsche Part found by using our original Porsche Part Number Search. If you are ordering parts via this method it is your responsibility to make sure that you enter and purchase the correct products for your vehicle. Please only use the searched product if you are sure of the part numbers as parts cannot be returned if ordered incorrectly.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90008214201L
91137504300
90008214201
The product you are viewing cross references to these numbers
Price: €14.59
In stock