Hi Dodge.
There is no way of telling what your body number or chassis number will be from the engine number.
There are a few reasons for the this.
First and foremost because engines were not fitted into the chassis in any number sequence.
Secondly, many cars have had replacement engines in their history.
To identify your car there are a few places to look.
As you mentioned the radiator shroud we will start there.
Depending on what year your car is the number on the rad shroud will be either the body number or the chassis number.
There is a difference of about 500 (rarely exactly 500) between these two numbers. Again, this is because the bodies were not kept in any specific sequence, as Cooper S appear to have been built in batches, bodies were put out of sequence if they required two colours (as most did) or if their was any rectification needed - meaning the car was taken out of sequence for the rectification.
If your car is a Mk1 or post-1969 Mk2 then the number on the shroud should be the body number.
Again, because of the above reasons, knowing the body number will not give you the chassis number.
However, the body number should have M2 / 06 before the number. This is sometimes in a circle but not usually. The 06 refers to YDO6 - a Cooper S. If it is 05, then it is YDO5, or a Mini De Luxe. Having M2 / 06 at least tells you the car is a Cooper S.
If your car is Mk2 from 1969 or very early 1970, then the number on the rad shroud will be the chassis number. If this is the case then the prefix to the number will by YG2S4, instead of M2 / 06.
The YG2 should be one stamping, the 4 is a separate stamping.
If the number prefix is YG2S1 then it is a Mini K. If it is YG2S3 then it is a base-model Mini 1100. So, it should be YG2S4 for Cooper S Mk2.
If this is the case for your car, then the body number, again about 500 less than chassis number, should be stamped into the scuttle drain channel (at the rear edge of the bonnet aperture). Again this should M2 / 06 (as the Mk2 Cooper S was still a YDO6 model).
OK, if your car has the body number on the rad shroud (ie it is a Mk1 or post-1969 Mk2) then the chassis number will be stamped into the fire-wall just behind the brake or clutch master cylinder.
If you are not sure of the age of your car, or if it was originally Mk1 or Mk2 (it should be a Mk1 if your engine is the original, so that gives you somewhere to start) then have a look to see where the ID or Compliance plate was fitted. Look for the four pop-rivet holes. A Mk1 would have an ID plate fitted to the firewall behind the master cylinders, just above where the number is stamped into the body. This number should of course match the number on the plate.
Remember, the body number was stamped before the body was painted, so is often full of paint and hard to read. The chassis number was stamped in after the car assembly was finished, so is often easier to read - however, if the car has been repainted at any stage then this may also be full of paint and very difficult to read.
So, there you go.
Happy number hunting.
Let us all know how you get on and what the numbers are that you find.
Cheers,
Watto.
