IffyG 
Over the last few weeks I've been having issues with intermittent long shifts from 3 to 4 and difficult 4-3 downshifts on the highway. Yesterday I was merging onto the highway and the it banged through the 3-4 shift.
Today I swapped out my poly motor mounts and brackets with a pair of brackets and rubber bushings I picked up from the junkyard thinking that my mounts might be amplifying the issue. I took it out on the highway and was carefully monitoring the 3-4 shift and the 4-3 shift on both the tach and my Aeroforce. The 3-4 shift seems to go smoothly most of the time aside from the occasional long shift and the bang into 4th I experienced yesterday.
The 4-3 downshift on the other hand seems to be royally screwed. Once the car is cruising in fourth gear (per my Aeroforce), I accelerated to induce a downshift. The RPMs would initially jump with minimal acceleration, the transmission downshifts and the RPMs drop approximately 300-400 before 3rd gear finally catches and the car continues accelerating.
I've been through a few transmission scares, so I have checked everything that caused bad shifts in the past (my trans fluid is full, battery is good, cat is good, MAF is good) and can't come up with anything else easy to check before I haul it to a shop for a diagnostic. Any input would be appreciated.
