I agree with this and I aplogize for not responding to your PM.
If you use google image and look up T slot restriction you can see which holes feed the T slot. You need to measure both passages...the short passage that is where the metering block bolts up and the vertical passage through the main body that actually goes down to the base plate and T slots themselves.
They are usually .109ish and the vertical passage may be a bit smaller. You can use an 8/32 brass set screw and use about an .080-.082 hole to start as a restriction and tune from there.
Sometimes, you can open up the top emulsion hole in the metering block to clean up the cruise a bit. A couple of thou is a start on those, but that should be your last tuning change.