Tranny linkage adjustment

I'm running Pennzoil synchromesh GL-4. Just changed it over the winter and the old oil was SAE 30wt. and I didn't notice any gold or metallic sparkle to it.
The linkage is all adjusted properly and has metallic bushings and are all snug.
With the engine off, I can shift through all gears with no problem or binding including reverse.
With engine running, it grinds going into reverse no matter what I do. I've tried double clutching, putting it in all other gears then going to reverse.......
One thing I noticed, If I adjust my clutch to have any space between my throwout bearing and the pressure plate levers, then I don't get enough disc departure and the car creeps in gear and is tough to get into first. Could this have something to do with the grinding?

You should have .06 of an inch departure between the clutch and flywheel or pressure plate. Is the pressure plate correct for your car? Are the fingers at the correct height? If yes, then you may be getting deflection in your linkage. Or you may need a longer lower arm on the Z-bar to get enough travel, doubtful. Creeping in gear with the clutch in, or a throwout bearing always touching, is very bad. It does not sound like a shifter problem, so far.

As others have said, You should run the overcenter spring with a anything except a diaphragm pressure plate.