diffs in 1030500080 hydro lifters

[bereng]

Hi,

so I am replacing the hydro lifters in my M103 engine. The new ones just won't go into the rocker arms.

See this lifter from the internet:



It's top ring has small dents. These prevent the lifter from getting in the rocker arm. This one has the ring completely flat, so would fit smoothly I guess.



Does anybody know why these differences and how can I fit my lifters?

Thanks