I believe Morel uses the same body for both the Hydraulic and Solid roller lifters, They must insert a solid "plug" in their solids to take up the space.

My issue is for smallblocks I would rather have a shorter (lighter) lifter body and a longer pushrod to minimize the effect of the bad geometry. For that reason i switched to the mush shorter and lighter BAMs

But on a big block maybe a shorter pushrod is actually better. I've had no issue with the Morels (who make the "house lifters" for nearly everyone)

The last Hydraulic Roller I built I used the early style cranes and I have had Zero issues in a big block turning up and just over 7000 and that on 2 different cams.