Trans troubleshoot.

[NTRCOOL]

I have been noticing a slight issue with the trans in my Black 90 I changed the fluid and filter about a year and half ago it was a major improvement. I stored it over the winter and didn't get a chance to start it at all till two months ago. I have been driving it off and on for the past few weeks, and I am noticing a fluctuation in RPMs as I am cruising at a steady speed. It seems as minor as if overdrive cannot make up its mind to stay engaged or not. So my first thought is that The Torque converter is starting to give up Overdrive lockout. I checked the fluid and it seemed to be near the right level, but I noticed a few small bubbles on the dipstick. Any Ideas?

[Shifter23]

Small bubbles are normal on the end.  But are you sure it is the torque converter or maybe the TCC solenoid?  Call me sometime on this Matt.