ix brake booster

[g22]

I was under the impression that the e30 325ix and the e34 M5 / e32 735i brake boosters were the exact same part. In looking at Real OEM the e30 has a different part number than the others.

What's the difference between the boosters that would cause a part number change?

Thanks

http://www.realoem.com/bmw/showparts...03&hg=34&fg=25

http://www.realoem.com/bmw/showparts...86&hg=34&fg=25

http://www.realoem.com/bmw/showparts...=34&fg=25&hl=1