Truvativ/ SRAM crank installation

leonlikestrees

I'm installing some SRAM Rival cranks, and I'm just amazed how hard I have to tighten the LH arm down. I'm using a real He-Man effort on a fairly long 8mm allen key, and the play still hasn't all gone.

I don't remember ever tightening anything up so hard on a bike before - am I doing something wrong?

I'm sure the tapers are aligned, and the threads aren't crossed.

Any tips or past experiences appreciated.