Do failing synchros always result in a "crunching/grinding" symptom or can the symptom be simply "hard to get into gear" with no crunching/grinding?

As my transmission warms up, it can be difficult toget it into 2nd or 3rd gears when standing still. It is very erratic. You can get it into gear 5 times in a row, and the next time it will not go in - no discernable pattern.

I have all new bushings, a new Weltmeister short-shifter, and fresh transmission oil.

This is a V8 conversion so I do not use 1st gear. (The original 2nd gear is my 1st gear - hence the need to put it into the original 2nd gear at a stop).

or you need to adjust the clutch.....

worn dogteeth and worn sliders make for crappy shifting like you describe.