They are difficult to see, when you stand at the radiator the numbers are on your right side, they are set back on the cast iron and not on the alloy casings, Also the numbers are etched on with a series of dot/stars and not stamped on as they used to be. So you may have to use a bit of kero on a rag and give it a clean so you can see them, I had to use a mirror as I could not read the last digit without it.
oh, my bad, front left side of block, so on your right side when looking at the motor.
Was checking the wrong side haha
Ill have another look tomorrow in the light, should be able to find it now that ill be looking in the right spot, thanks everyone for their help.