I recall having a chance to take a good look to compare a US market head & a European head about 18-20 years ago when the latter was being prepped to install on what now through a long chain of events has become my car. At the time, some friends and I bought a few European heads w/ cams and this one was the only one that got properly prepped up & installed (with a different cam as it turned out). Unfortunately, I ended up selling mine after I sold the X1/9 I sold at the time & I was sure I'd never own an X1/9 in the future. Ha!