Head dowel pins not matching up

[E30Gus]

I'm in the middle of a 2.7i build from my 88 super ETA bottom end. I went to install the 325i (885) head today and noticed the block only had one dowel pin because it got stuck in the old head. So I grabbed one from another block and put it in the available spot on the block. After 2 tries to mate the head, the back side would not seat on the block. I noticed the dowel pin on the block is in a different spot in relation to the receiving portion on the head dowel pin spot. Both heads are 885 so I'm confused why the heads vary in pin placement. I ended up installing the head without the back side dowel pin. I'm concerned now about alignment. Exactly how important is it to have both pins installed? And if I have to remove the head again to install a pin for the back, how is this done since they don't mate up?

Thanks,
G

[digger]

they are all the same, one is between 1&2 on inlet side and the other between 5&6 on exhaust side. its probably just been distorted so doesnt go in.

yes you need to align otherwise piston to head and piston to valve clearance might be way off and......

[E30Gus]

Ah $50 mistake! I guess the dowel pin was in crooked?
I'm going to slightly bevel the head hole to help with mating after the new parts come in.
Thanks