Can anyone help decode an engine number & vin?

Started By: Larry Ahlgren on 2005-01-05 05:52:19

I just bought a 1959 Mark IX, it's rough, but with a little work, it'll be a driver. It's LHD, silver/red, with a manual trans.
The vin is 7907749BW. Am I right that the BW calls out a Borg-Warner automatic trans?
The engine number is 7D56704-8, and the cylinder head is a red/orange color. Any ideas on what the engine is and where it started out?


Larry Ahlgren
St James, NY
Jaguar Mark IX
BMW 600


I have a 1959 Mk1 VIN S991007BW and it certainly has a BW automatic transmission...

David Bates
1959 Mk1 Black/Red

One clue re the transmission is the seating arrangement. Automatics had a bench seat. Manual had two buckets as standard. A bench could have been substituted as an option, I think, but the gearshift would be inconveniently close to the seat.

John Horen

Guessing that your vin is 790749 and not 7907749 your car is the 784th LHD Mk IX built out of 4021 total. The BW is for the Detroit Gearbox licensed to Borg Warner (that is why it is a model DG---. As for the engine the block is from a 420G most likely and the head number should match. You do not have 3 carbs in there do you? As far as the color I guess Pep Boys had a sale. It would be interesting to see the modifications made to get the 4.2L to mount up in that body. You said you have a manual trans. If it was taken from a 420G as a unit do uou have overdrive? Good luck George Camp

1957 XK 150 D.H.C.
1962 MK 10 4 manual o/drive
1965 3.8S
The 4.2 litre engine fitted to the MK X of 1964 started with 7D50001
and continued until the end of 1966,when the 420G came into production.At
the end of 1966 there were still a number,reported to be about 75 cars,of
4.2 MK X's sitting in Montreal.These were converted into 420G's becaues it
was mostly just trim that made them different with the exception of the serial numbers,but who was to know.The 9:1 cylinder heads were a gold colour and the 8:1 were more of an orange colour similar to the XK 150S.
There were 5119 MK X's built plus 18 limo's.Please take note that the engines delivered to each car were in assending numbers but not all of them went only into the MK X.The motors were used for many other products
including fire fighting and machinery such as military equipment.I have the "Jaguar Vehicle Identification Listing" supplied to the Dealer Network
that shows car and engine numbers for each model.For the listing of 420G
it shows 1666-68 G1D.... 7D....
They have no record of what chassis or engine number was the first one.
I have never seen a 420G,a real one,with a painted head.I can check with a retired friend of mine that used to own a Jaguar Dealership.

The engine falls in the range of the 420Gs. I take issue with your assertion that a 420G is just a trimmed-up MK 10. My 420G IPL has 18 pages of foolscap small type of differences between the two. Your other stories are interesting. Can you document any of them? George Camp

Can someone tell me what the letters in the VIN of my Jaguar should be telling me...S987401DN. Thanks for your time and efforts. Merry Christmas.....