shorter TOB? sachs vs oem, same part numbers, but different...

[er1k325]

im in the process of gathering all the parts do do a clutch job and everything else "while im in there".

I have purchased the bimmerworld JB racing flywheel clutch kit, which came with Sachs disc, tob, pp. i decided to order a OEM TOB to use instead of the sachs one included.

Same part numbers, one is dealer part other is sachs part. the oem one is slightly shorter than the sachs.

same part numbers, so what gives?
which one should i use? i will definetly compare them to whats already on the car when i eventually get around to doing the clutch job. but was just very curious when i noticed the difference right now, was wondering if anybody has ever noticed?

[asianvenom]

If you look closely at the clutch disc, if it's made by "LuK", then your TOB is a later revision.

Like this