Valve spring micrometer

I'm having a horrible time getting this thing to work correctly I'm I doing something wrong any tips or tricks? I have gotten four of my intake side and 1 on my exhaust side I'm having a horrible time getting the keepers in and the when I do get them in I cant get them back out. The tool just doest seem to collapse enough to give me adequate clearance for the keepers. You can see in the photos the one side goes in but the other is extremely tight. Iv damages several keepers already on the intake side trying to get them out. Any help is appreciated btw these are small block heads and I am using the 1.4-1.8 tool from summit I can5 find a shorter one than that.

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