All the gears and sliders have some heavy assembly lube on them and some of the rings may be stuck to the hub on the gear.Make sure you push the clutch in before you try testing the shifter into the gears.
When you want to circulate the fluid put the trans into 4th gear,have someone hold the clutch in while you turn the driveshaft/wheels.That way it will coat the cluster and all the drive gears when they rotate through the lube.
I will call you tomorrow to see how it's going
Gus