First off - how can i change my member name to include the model/year/mileage of my car?

My transmission shifts up at what seems to be high rpms and won't go into 4th - at a constant 60 mph its doing 2750 rpm. I don't drive hard, and accelerate gently so its not a heavy footed operator issue. Also, when i take my foot off the accelerator, the transmission seems to slow the car more than i would expect. The transmission was replaced/rebuilt by the previous owner in the last 40k miles.

I've read some recent threads about turning the modulator on the side of the transmission to make shifting smoother but could doing that also correct my problems? If so, where is the modulator, how do I adjust it and which way should I turn it?