Steve, on the side of the block, does your Cortina engine have the number 711 cast into it. May have other digits around it. If there you can't really miss it unless it is covered in cobwebs/grime/bird nests! If so that is a hard to come by engine now and is THE one for Historic Formula Ford single seaters. So long as it is in standard tune ie not machined, bored out, ported etc etc. I have a spare one in my garage in HFF tune that is in good order. I have already turned down £2,000 for it. Have a look and let us know.....