2.25 7:1/8:1 are both the same if i recall, for example you can skim a 7:1 to make it 8:1

https://www.automotivecomp.com/wp-content/uploads/2019/01/2.25-Petrol-cylinder-head-identification-min.pdf May be useful

Good afternoon folks. I am after some advice and assistance regarding the cylinder head. I currently have an old series 2a early/mid 60's 2.25 petrol engine with the compression ratio 7:1, thats going by the casting number on the head. The head...