85 SS Shifting Fast, High Idle 4th Gear. Why?

[pawnfather2130]

I recently purchased an 85 Monte Carlo SS. I noticed that it shifts really fast, and the idle stays high when in 4th gear or OD. It stays at about 4000-4500 rpm if running at 45-55 mph. Naturally, if I go faster, say 60-65 my rpms go to 5000-5500. To the best of my knowledge, the car is stock, or as I was told by the seller. Any parts that were replaced were replaced with OEM Delco parts. Can anyone help me figure out why it does it, and what may be done to fix it? As it stands I am getting about 6-8mi per gallon now... I have owned this type of vehicle before and know it can do better than that... Thanks in advance for any assistance possible.
Scott

[slimfatboy]

not to suggest the worst, but are you sure you have the 2004r? when i bought my first monte(86ss) the guy swapped in a 350c. comparison chart here. http://www.maliburacing.com/auto_tranny_id.htm
i would do about 3500 rpm just driving around town. sounds cool but not affordable anymore. it would scream going from town to town so i stopped driving it other than to get groceries until i got another trans.

have you adjusted the TV cable? hth