BMW m20b23 1983 cylinder head very clean inside. Had rebuild then only did a couple of thousand miles. Believed to have larger profile cam as when fitted to my e21 it made a very healthy amount of power on the Dyno if I remember it was around 160bhp which is better than the stock 141bhp. This head has larger ports than the e21 head so a fantastic upgrade for 320/6 and 323i engines.