Im not sure what Z paste is but there are some questionable cam lubes out there.
Excellent decision to remove the inners.
Excellent decision to use a dedicated break in oil.
Just make sure you have a known good carb and ignition.
Drop the distributor in and line it up so it has at least 30 degrees of timing on it when it fires. 40 degrees is even better. Retarded timing builds exhaust heat and that will stick exhaust valves.
A small oil or water leak isn’t an issue so keep the engine running unless it’s gushing leak.
I start at 2500 RPM and cycle the engine up to 3k or so for a bit and then down to 2k for a bit. Varying the RPM helps keep the lifters rotating.
Once you get through the 20-25 minute break in cycle, cut the filter open and get a look. Drop your inners in and do another 15-20 break in cycle.
Cut the filter open again and if it’s clean screw a new filter on it, change to your regular oil and go beat the snot out of it.