Front shock to mount fit

[pghmailman]

I have an appointment tomorrow for front shock replacement, tie rods ans alignment. I ordered Billy sports and new mounts based on my vim and manufactor date. When I placed the shock through the mount in a dry run the shaft diameter is smaller than the mount hole. Not by much, a couple of mm tops. Question is there a bushing or shim of some kind that slides around the shaft? The threaded part of the shaft is the same diameter as the one on the car now. I just don't want to take it down and have them rip one side apart only to find I got the wrong parts.
Bearing part # 31 331 139 437
Bilstein # F4-P36-3018-H1
car is 540i US version manufactor date 3/93

Thanks

[uk525td]

3 different top mounts, for 2 different shock diameters
i tried to bodge this before and it didnt happen
but ive been told bilsteins "may" come with sleeves to take up the difference