Bilstein shocks often come with the same size mounting eyes on each end. We often get asked “Can I mount them with the shock boot up, does it matter which side is facing up?”
The majority of Bilstein shocks mount with the boot on the top of the shock. Bilstein does have some shocks that do have the boot on the bottom of the shock and the same size mounting eyes on each end. As a general rule with all Bilstein shocks, you should pay attention to the label. Bilstein tech advises that you should always mount your shocks so that the Bilstein logo is right-side up.
Above is Bilstein rear shock 24-186742 for the 1999-2010 Chevy Silverado and GMC Sierra. The shock has 14.1 mm mounting eyes on each end. The correct way to install it is with the boot on top and the logo facing the correct way.
Above is Bilstein rear shock 33-187419 for the 2009-2013 Ford F-150. The shock has 12mm eyes on each end, so it could be mounted either way. The correct way to mount it is as shown with the boot down and the label facing so it is not upside down.
So, If you are not sure which way is up on your shocks or wonder if you can mount them either way, always look at the Bilstein logo. If it is upside down, so are your shocks!