I was convinced, after reading Dr Google, that the number was on a flat spot on top of the engine block between number 1 & 2 exhaust outlets. When I initially could not find it here, I removed the extractors & gasket so I could get a better look but still, no numbers. I even researched metal etching and made up a special mix that would reveal worn or ground away numbers. Again, no numbers. Here are some pics of where I originally looked.
The engine block has 2 or 3 other flat spots around it so I started cleaning them off with sand paper and one, right at the rear of the engine revealed the number 44. Some research stated that this was an engine code but not an engine number. Not what I was really after!
Some more looking on Dr Google said it was between the water pump & the thermostat but I still could not find it. It was getting to the stage that I was convinced the motor had been replaced at some stage in the 30 years prior to my ownership and I may have to do something that I didn't want to do and that was to stamp the numbers again.
At a recent car show I asked the owner of a Cortina GT with a similar engine where he thought the engine number was. He was quite experienced with these engines and showed me where his was, on the other side of the engine, just above the oil pump. I was a little confused as the numbers he showed me were cast into the block, as most engines have to distinguish the type of engine eg, 711M. Anyway, I had not looked very hard in that spot as my car has so many hoses, plus the distributor and wires, that it is a very difficult place to work in. So, on returning home, with my brightest torch, I started looking again. My engine had no such numbers as he had shown me on his Cortina! OK, foiled again!
So again I started looking very carefully around the back of the block & then around the front near the water pump and I thought I could see the letter A, which is the last letter of my number. It was at the front of the engine block, in a relatively difficult place to see, but a start. I then got a screw driver & started to scrape away the paint & guess what? Some numbers started to appear & they were checking out what I though they should be. After more cleaning with sand paper & a wire brush, all the letters & numbers started to be revealed, indicating what I had hoped for - that they matched the compliance plate. A smart phone camera is a great help in these tight spots as the flash can really highlight the small numbers that you are looking for.
Some of you who are experienced with this engine will have known this all along, but nowhere in my research did it say to look in this spot - centre front, top of engine block.
Finding this number confirmed my belief that I had an original car with matching numbers as you can see in the photos all the numbers are the same, including the body number found on the driver's side suspension turret.