Tranny linkage adjustment

SSG, I'm thinking internal if you've gone through all that.
Coming from any gear going to reverse it grinds the same?
Using gear lube? Last time changed? A lot of gold speckles in the old?

Shifter/linkage.... Do you have metallic as opposed to nylon bushings for the shift rods? Make sure they aren't worn and/or sloppy.
Pull the boot off so you can see the gate. Engine off, shifting out of 1st going to 2nd. Is the gate dropping all the way consistently and not bouncing through the travel?
With a helper shifting through the pattern can you see two rods trying to move at the same time?