Component Serial Numbers
The following information was taken from various sources including e-mail from David Huddleson, which got me started on the project. Special thanks to Keith Bennett who has a great page full of Serial number info (for all Triumph models). Keith put me onto one of his sources, Bill Bolton. Bill was good enough to send me a copy of his article for reference. Given the amount of contradicting information I was able to find (even between manuals and catalogs), it is fair to say that there is a lot of confusion on this topic, so I wouldn't be surprised if there were some errors below. A Locator Guide is available to help you track down the Serial numbers on your vehicle.
TR7 Component Serial Numbers
| Model Build Year | Engine | Gearbox | Differential Ratio |
| 1975-76 Coupe (ACL) | CL | CG- 4spd | CG - Man (3.63:1) |
| N. America | CL - 5spd | CH - Man (3.9:1) | |
| 027M - Auto type 65 carb | CT - Auto (3.27:1) | ||
| 1976-78 Coupe (ACG) | CG | CG- 4spd | CG - Man (3.63:1) |
| UK/Europe | CL - 5spd | CH - Man (3.9:1) | |
| 027M - Auto type 65 carb | CT - Auto (3.27:1) | ||
| 1977-78 Coupe (ACW) | CV | CG- 4spd | CG - Man (3.63:1) |
| N. America | CL - 5spd | CH - Man (3.9:1) | |
| 027M - Auto type 65 carb | CT - Auto (3.27:1) | ||
| 1977 Sprint (ACH) | CH | CL - 5spd | CH - Man (3.9:1) |
| UK | |||
| 1978 DHC (ACT) | CV | CG- 4spd | CG - Man (3.63:1) |
| N. America | CL - 5spd | CH - Man (3.9:1) | |
| 027M - Auto type 65 carb | CT - Auto (3.27:1) | ||
| 1978-79 Coupe (TCG) | CG - UK/Europe | CL - 5spd man | CL - Man (3.45:1) |
| UK/Europe/Aus./Can. | CL - Aus./Can. | 027M - Auto type 65 carb | CH - Man (3.9:1) |
| CT - Auto (3.27:1) | |||
| 1978-79 Coupe (TCW) | CV - Carb. | CL - 5spd | CL - Man (3.45:1) |
| N. America/Canada | CK - EFI | 027M - Auto type 65 carb | CH - Man (3.9:1) |
| 063J - Auto type 65 EFI | CT - Auto (3.27:1) | ||
| 1978-79 DHC (TCT) | CV - Carb. | CL - 5spd | CL - Man (3.45:1) |
| N. America/Canada | CK - EFI | 027M - Auto type 65 carb | CH - Man (3.9:1) |
| 063J - Auto type 65 EFI | CT - Auto (3.27:1) | ||
| 1980 DHC | CK - EFI | CL - 5spd | CL - Man (3.45:1) |
| N. America/Canada | 076N - Auto type 66 Carb | CH - Man (3.9:1) | |
| 077K - Auto type 66 EFI | CK - Auto (3.08:1) |
| Final Drive Ratios - TR7 / TR8 Differentials | ||
| Final drive ratio used with 4 spd gearbox | 3.63:1 | |
| Final drive ratios - from VIN 402047 | ||
| Rover 5 spd | ||
| United Kingdom | 3.90:1 | |
| Europe | 3.45:1 | |
| U.S. / Canada (1975-80) | 3.90:1 | |
| U.S. / Canada (1981) | 3.45:1 | |
| Borg Warner Automatic | ||
| 1975-1978 | 3.27:1 (type 65) | |
| 1979-1980 | 3.63:1 (type 65) | |
| 1981 | 3:08:1 (type 66) |
TR8 Component Serial Number Prefixes
| Model Build Year | Engine | Gearbox | Differential Ratio | Comments |
| 1978-79 FHC (TCN) | 10E - Fed Man | 15A - Man | CK (3.08:1) | Pre-production Coupes |
| 11E - Fed Auto | 051N - Auto | |||
| 12E - Cal. Man | 15A - Man | |||
| 13E - Cal. Auto | 051N - Auto | |||
| 1978-79 DHC (TCV) | 10E - Fed Man | 15A - Man | CK (3.08:1) | N/A |
| 11E - Fed Auto | 051N - Auto | |||
| 12E - Cal. Man | 15A - Man | |||
| 13E - Cal. Auto | 051N - Auto | |||
| 1980 EFI | 14E - 5 spd | 15A - Man | CK (3.08:1) | Federal or California |
| 15E - Auto | 051N - Auto |
All TR8 automatic transmission equipped vehicles used Borg Warner type 65 units