Thanks every one. I found a 7 on the machined flat in the middle of the left hand side of the head. Also the compresion tests point towards a 7:1. I just did a 400 mile trip with a 1.5 tonne boat in toe and got 15.5 mpg. Must be the 750 tires, extractors, free flow exhaust, and airfilter doing...

Hello all. I have a S3 904xxxxxxx engine that should have a 7:1 compression head. It has been reco'ed and some one has put extractors on it so I'm wondering if they didn't put an 8:1 head on it. The only numbers on it are 568750 and 12G. Is this a 7:1 or 8:1 head? Or can I get a rough idea from...