Chassis numbers
Six-digit blocks by body style, with left-hand drive offset by exactly ten thousand from right-hand drive.
| Body style | RHD from | LHD from |
|---|---|---|
| Open Two Seater | 800001 | 810001 |
| Fixed Head Coupe | 804001 | 814001 |
| Drophead Coupe | 807001 | 817001 |
What the letters mean
The prefix records the specification and the suffix records the transmission.
| Mark | Meaning |
|---|---|
| A | Special Equipment, standard cylinder head |
| S | Special Equipment, C-type cylinder head |
| No prefix | Standard specification |
| DN | Laycock de Normanville overdrive |
| BW | Borg-Warner automatic |
So a chassis number reading S818689BW is a left-hand-drive drophead coupe, Special Equipment with the C-type head, on automatic transmission. One reading 804053DN is the fifty-third right-hand-drive fixed head coupe, standard specification, with overdrive from new.
Engine numbers
Prefix G, from G1001, running to approximately G9980. The format is G####-<digit> with an optional trailing S.
The trailing S means a C-type cylinder head. The digit denotes compression ratio.
Gearbox numbers
| Prefix or suffix | Meaning |
|---|---|
| SL or JL | Standard Moss box, no overdrive |
| JLE | Overdrive box, XK140-specific |
| E, N or S ending the prefix | Laycock de Normanville overdrive |
| CR, MS or J suffix | Close-ratio gears |
XK140 gearboxes have different tailcases from XK120 boxes and are not interchangeable in that direction.
Where the numbers are
The body number sits on a plate attached to the left-hand side of the scuttle, under the bonnet. It is numerals only, with no prefix, and it is the least well documented number on the car — the great majority of XK140s carry no body number stamping on the bonnet at all, whatever you may be told.
The Heritage Certificate
The Jaguar Daimler Heritage Trust will issue a certificate from the factory build records giving the chassis, engine, body and gearbox numbers, the paint and trim colours, the supplying dealer, the date the car was despatched and the first owner.
What it proves is what left the factory. What it cannot prove is what is in front of you now. A certificate showing the right numbers is good evidence that a car is what it claims; it is not evidence that the numbers on the car are the ones the certificate describes. Check the car against the certificate, not the certificate against the advertisement.