Chassis and engine numbers

Numbers are how an E-Type keeps its identity across sixty years of repaints, engine swaps and changes of keeper. The shape can be altered and the specification can drift, yet the stampings tie the car in front of you to a line in the factory ledgers. This page explains the system in outline. It deliberately does not reproduce the full decoding tables, because the people who maintain those tables keep them current and this archive would only freeze them in time.

The four numbers

The factory recorded four numbers for each car, and a Heritage Certificate lists all of them:

• Chassis number. The identity of the car. This is the number quoted on registration documents and the one to protect above all others.
• Engine number. Stamped on the block. The 3.8 litre cars carry an R prefix, with RA appearing on engines built from early 1963. The prefix changed again for the 4.2, so an engine number also hints at the engine's original home.
• Body number. The identity of the tub as it came off the line. On a monocoque car the body is the structure, so this number matters more than it would on a chassis car.
• Gearbox number. Recorded for each car. Gearboxes are the component most often exchanged in service, so a mismatch here is the least surprising of the four.

The numbers appear together on a plate in the engine bay, and the individual stampings appear on the components themselves. Check the stampings, not only the plate. Plates are easy to replace and reproductions are freely available, which is innocent on a restored car and convenient on a dishonest one.

Reading a chassis number

The chassis number has three parts worth understanding: a prefix, the sequence itself, and occasional suffix letters.

The sequence and its ranges identify the model, the body style and the drive side. Series 1 numbers sit in ranges allocated separately to right-hand and left-hand drive roadsters and coupes, Series 2 numbers begin with 1R, and Series 3 numbers begin with 1S. Within each range the number rises with production, so published tables of first numbers by year let you place a car within an approximate build window.

Suffix and prefix letters record equipment. The Heritage Trust's research guide lists DN for a Laycock de Normanville overdrive and BW for a Borg Warner automatic, the latter found on Series 1 4.2 litre cars, on the Series 2 2+2, and on all Series 3 models. A P prefix denotes power steering; it does not appear on Series 3 cars because power steering was standard by then. An automatic suffix on a car that is now manual, or the reverse, is a fact about its history that deserves an explanation.

Using numbers in practice

The practical routine is short. Read the plate, then find each stamping on the car and confirm they agree. Look up the chassis number against the published ranges to check the car is what it is described as: a Series 2 prefix on a car sold as a Series 1 is exactly the kind of thing this catches. Then compare everything against the Heritage Certificate, which is the only document that states what the factory recorded.

Expect some mismatches on an old car and judge them individually. A replacement engine of the correct type, openly described, is normal sixty-year-old-car life. A chassis number that has been ground, restamped or presented on a fresh plate with no explanation is not. The buying and evaluation page covers how to weigh what you find, and the series identification page covers the visible features that should agree with what the numbers claim.

Common questions