Stant 27266 Thermostat Seal – Fitment Guide for Ford, Mercury (1972–1979)
Ford, Mercury (1972–1979)
Stant 27266 Engine Coolant Thermostat Seal – from Don's Obsolete Auto Parts
Keep your car or truck on the road with a genuine Stant 27266, the Stant thermostat seal for Ford and Mercury V6 159 and 171 cu in (2.6L/2.8L) engines: 1974–1978 Mustang II, 1979 Mustang, 1975–1979 Pinto and Bobcat, and 1972–1979 Mercury Capri. A thermostat seal is a molded rubber ring that seals the thermostat or the water outlet instead of a flat paper gasket. Stant's description of these seals: no sealer or RTV is needed, and each one is shaped for its application.
Key Features
- Part Number: Stant 27266 (single pack); same seal as Stant 25266 in the Stant catalog
- Type: Engine coolant thermostat / water outlet seal (rubber, square-cut style per the Gates equivalent)
- Size: about 1.81 in. inside diameter × 2.094 in. outside diameter × 0.094 in. thick (Gates 33606 data for the direct equivalent)
- Cross-references: Gates 33606; Carquest 30966; Dayco 82501; Dole WO-35094; Edelmann 6031; Fel-Pro 35094, 8E35094, K12485; Ford D2RY 8590 A, D4PZ 8590 B, D4ZZ 8590 A; McCord 74-0004
Stant's own 1928–1994 application catalog lists the 27266 for 2 makes from 1972 to 1979. It's a good fit for restoration projects, weekend drivers and mechanics keeping older vehicles running.
Compatible Makes & Models (from the Stant catalog)
- Ford (1974–1979): Mustang (1979), Mustang II (1974–1978), Pinto (1975–1979)
- Mercury (1972–1979): Bobcat (1975–1979), Capri (1972–1974, 1976–1979)
Note: Always verify fitment for your specific year, make, model and engine. Some catalog lines are limited to one engine code or housing type; the full engine-by-engine list is in the fitment appendix below. If you have your old seal, compare its size and shape, or just ask Don and Kathy.
Price is $9.95 plus $3.00 for shipping. Don and Kathy offer a fair deal for this. Buying for a club, a shop, or a whole fleet of project cars? Even better.
Why Buy From Don & Kathy at Don's Obsolete Auto Parts? Don Leask founded one of the earliest online obsolete auto parts businesses (carparts2 on eBay in 1997, the second auto parts store on eBay) and grew it to 11,000–17,000 unique listings. Today, with help from their digital agent Misty ([email protected]), Don and Kathy connect directly with restorers and collectors while preserving their legacy of quality parts. These seals come from Don's own shelves.
To reach them, click the "Don & Kathy Leask" button at the bottom left of any page on donsobsoleteautoparts.com, or email [email protected].
The Stant 27266 Thermostat Seal: The Right Seal for Ford and Mercury Owners
Thermostat seals are small, but they decide whether a cooling system stays dry. When the thermostat housing comes off, the right seal is the quiet part that keeps the job from turning into a second trip to the parts counter.
Why This Seal Matters Stant's application catalog covering 1928 through 1994 lists the 27266 across 2 makes (Ford, Mercury). Cross-reference tables tie it to the Stant 25266 and Gates 33606, which makes it easy to match against an old parts list or a worn-out seal.
Real-World Fitment Examples
- 1979 Ford Mustang V-6 171 cu in
- 1975–1979 Mercury Bobcat V-6 171 cu in
Keeping Older Cars on the Road Don and Kathy Leask have been part of the classic car world since the early days of the internet. Starting with carparts2 on eBay in 1997, they became one of the largest online sellers of obsolete parts. Now, with their Don's Obsolete Auto Parts site and digital agent Misty, they're making hard-to-find parts discoverable again, connecting owners of rare inventory with the enthusiasts who need them.
Buying Tips
- Match three things before ordering: year, model and engine. Watch for catalog notes such as engine VIN codes or housing type.
- Compare sizes: the 27266 is about 1.81 in. inside diameter × 2.094 in. outside diameter × 0.094 in. thick.
- Some engines use a gasket and a seal at the thermostat; check what came off yours.
- Restoration shops, clubs and collectors can ask about quantity pricing.
Fitment appendix — every Stant catalog line for
27266
Source: Stant Thermostats, Gaskets, Caps – 1928 through 1994 (application pages). Format: Model — years [engine: years (catalog notes)]. Catalog coverage ends with 1994 models.
Ford
- Mustang — 1979 [V-6 171 cu in: 1979]
- Mustang II — 1974–1978 [V-6 171 cu in: 1974–1978]
- Pinto — 1975–1979 [V-6 171 cu in: 1975–1979]
Mercury
- Bobcat — 1975–1979 [V-6 171 cu in: 1975–1979]
- Capri — 1972–1974, 1976–1979 [V-6 159 cu in: 1972–1973 | V-6 171 cu in: 1974, 1976–1979]
Cross-references (full)
- Gates: 33606
- Carquest: 30966
- Dayco: 82501
- Dole: WO-35094
- Edelmann: 6031
- Fel-Pro: 35094, 8E35094, K12485
- Ford: D2RY 8590 A, D4PZ 8590 B, D4ZZ 8590 A
- McCord: 74-0004
- Motorad: MG21
- Motorcraft: RTS-5
- NAPA: 1066
- Pep Boys: 35094
- Standard Thomson: 1066
- Tru-Temp: 1066
- Waltham: 1066
- Stant equivalents: 25266, 30966, C66
Sources
- Stant Thermostats, Gaskets, Caps – 1928 through 1994 catalog (scan on Internet Archive): https://archive.org/details/StantThermostatsGasketsCaps1928Through1994OCR637Pages — part-number index ("Make / Year(s)" table at the back of the catalog) and application pages (PDF pages 449, 450, 451, 509, 510). Every catalog line pairs "Thermostat Seal 25266" with "Thermostat Seal (1 Pack) 27266".
- PartsHawk – Gates 33606 (interchange lists Stant 27266; style and dimensions): https://partshawk.com/gates-33606-engine-coolant-thermostat-seal.html
- AutoPartsPrime – Stant 27266 ("Engine Coolant Thermostat Seal"; UPC 033342072664; vehicle list): https://www.autopartsprime.com/stant/engine-coolant-thermostat-seal/mp-27266
- PartsHawk – Stant 27266 (fitment list): https://partshawk.com/stant-27266-engine-coolant-thermostat-seal.html