m30b35 rocker shaft question

[whelton25]

Well I am finally back to the grind, finishing up the assembly of my 1990 535i's engine. We were getting ready to put the rocker shafts in and noticed the new one I purchased was the wrong length. Turns out I didn't know there were two different lengths, so I just ordered the cheapest one I could online.MY question is, online they are listed EXHAUST front / rear or INTAKE front / rear, are there actual differences in the exhaust or intakes or just the front and rear lengths?Thanks folks!

[Binjammin]

They're all different.

[whelton25]

son of a b****. Might just end up with a whole set lol!

[Binjammin]

I'm confused though... you broke a rocker arm shaft?

[whelton25]

Also, how do you tell the different ones apart? Just so I don't screw anything up on the way in (which defines my teenage years)

[Binjammin]

Also, how do you tell the different ones apart? Just so I don't screw anything up on the way in (which defines my teenage years)

Easiest way to tell is that they only go together one way. You see the small cuts in each shaft? Those are for the head bolts. Line the shafts up with the head bolts, and they should be almost totally flush at the front of the head.