anyone else getting this. '83 280 w/141000. fresh tune-up with all the
goodies, including fuel filter. cant figure it out. HELP!

 

Hows the distributor? Any play in it?

 

mine runs the exact same way. My dash says 141, lord knows how many more miles are actually on it. Full tune up, valve adjustment, fuel filter, intake/ exhaust manifold gasket, just reset my timing back to about 12btdc which was at about 19 (yikes!) and set my idle back to about 800rpm right where it should be. I've replaced many of the vacuum lines. I've thought of just about everything it still idles kind of rough. I'm gonna do a compression test, i may have bent a valve or something, and I know i overheated it a couple of times when i had my coolant leak.

If I were you I would start by checking for vacuum leaks, check your timing and idle speed