Have a side shifter with good bushings and two repaired tunnel retaining clips. The issue is the difficulty getting into a certain gear moves around. I am always able to get it into gear but might take some force. What is bizarre is that the issue appears to be random. Anyone BTDT?

A couple of guesses - clutch cable tube is separated at the firewall or the clutch cable could need adjustment.

Maybe stretching clutchcable..on its way to failure in the end. If the issue is worse after longer drives... Is there enough fluids in the tranny ?

To clarify: I get that sometimes the symptom occurs and sometimes it does not, but does it happen on all gears or on specific gears? I think I know what you're describing. I (and others I've seen here) sometimes have an issue like this with 1st gear. Some of the time it goes in just fine, and other times it requires a little more force or moving the car slightly before it will engage.

I don't think it's the clutch tube. Normally when that goes, the clutch won't engage and you just get grinding (plus you mention new "retaining clips" which I'm going to assume means it's sufficiently anchored in the tunnel). I think it's something internal like you sliders, although I would recommend first inspecting and tightening your clutch cable to make sure it can fully engage and checking your gear oil level and condition.

Do those "good bushings" include the one at the firewall and in the shifter itself?

Which gears? Specifically. Esp bad in the r/1 2/3 planes? Examine the detent plate for r/1 and the detent/shift lever contact point for excessive wear. The 2 bushing that cradle the ball on the shift lever are part of the equation.

The gears which SOMETIMES th issues appar with are 3, 4, 5. The big issue right now is 1 and R. Adjusting the cable usually take care of the 1 and R issues. Adjusting the cable temporarily fixes the issue but the tension deflection is good.

As far as the bushings all were replaced a year ago including the firewall.

This is a 6 conversion. Thanks

Have you rebuilt the shifter itself?

With the engine off can you shift into each gear, easily finding them and feeling it shift into place?
If yes, the clutch related.