It is, I rebuilt it completely losely based on the Alpina C2/2 2.7L M20 engine only I used a 272deg Cam and they used a 268deg. Check my post here:

https://steemit.com/cars/@peterschroeter/7-years-in-the-making-2-rebuilding-and-restoring-a-30-year-old-bmw-twice

The rockers are mostly preventive as I haven't pushed the redline in the ECU, it's still around 6500rpm but I figured better safe than sorry. The cylinder head is really overdone for this but at least I know it's solid.