Gasket Kit, Cyl Head
T3990157 · Genuine Triumph
No date from Triumph yet
Listed for these motorcycles
Listed in Triumph’s parts catalogue for these motorcycles. Fitment is Triumph’s data, not a guarantee from us — add your motorcycle above and we check it against your frame number where Triumph splits the part.
Where it sits on the bike
Cylinder Head & Valves
Bonneville · Cylinder Head, Valves, Pistons, Liners, Camshaft & Balancers · callout 25
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Cylinder Head & Valves
Bonneville · Cylinder Head, Valves, Pistons, Liners, Camshaft & Balancers · callout 25
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Gasket Kit, Cylinder Head
Bonneville · Service Tools, Literature & Touch-Up Paint · callout 1
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Gasket Kit, Cylinder Head
Bonneville · Service Tools, Literature & Touch-Up Paint · callout 1
View diagram →
Prices and availability are a dated snapshot, not a reservation — Triumph supply is read from Triumph’s catalogue and our shelf count is read from our own system. Both move. Triumph supply checked Aug 5, 2026 · Brea shelf Aug 18, 2026. Shipping and tax are calculated at checkout.
Genuine Triumph parts from Southern California Motorcycles, 515 W Lambert Rd, Brea, CA 92821 · 714-256-6700