727 3rd gear feels more like a down shift

I was going through old threads in hopes of finding one that describes the trans problems that I'm experiencing and it sounds like this discussion hits the nail on the head. My issues are virtually the same.
I have a 727 with reverse manual valve body and trans brake. With my car when I shift from 2nd to 3rd gear the car slows just like the brakes are applied. The engine lugs down and if I leave it in 3rd it will stop the car. No burnt fluid smell. I race this car and it seems to grab 3rd properly when making a pass, although perhaps I'm just not noticing a lug at that time. It used to be fine and when going into 3rd it was a dead solid shift, the aluminum leaf bushings would clunk like a bugger.. The other thing is that I did have a stiff cable problem earlier in the year but was able to free it up with lubrication and by re-routing the cable. As I write this I'm wondering if maybe I still have a bit of a stiff cable and the shift valve isn't travelling the full distance when going into 3rd? Any thoughts on this anyone?