How to swap an M50, M52, M54 or S50 into your e30
So it has come to our attention that the legendary E30 DOHC wiki page is down and gone forever. So instead of letting it die, we have rehosted a copy of this guide. Keep in mind, this was the original work of the e30dohc-swap.wikia website that is no longer hosted. All credit goes to them. There is a wealth of information here that will help future e30 owners. Enjoy!
Link to E30 DOHC swap guide Wiki; https://www.garagistic.com/pages/e30-dohc-swap-basics-m50-m52-m52-and-s50