Now I wanted to ask, to what extent are the heads actually allowed to be crooked – in the longitudinal and plan direction??? And what do you think, is it better to mill them or rather grind them???? I found only this here in the forum:However, the engine repair shop said that the heads are crooked. 1/3mm “unplan”. Quer is probably 1/10mm and length 5/100mm allowed. However, in my eyes this is soon more a question than an answer! And that the head on the shorter distance may be more crooked than on the longer distance would be a little incomprehensible for me! Have both possibilities at work, but I would prefer to grind, since the surfaces are a bit finer and smoother?!!!!