My 1979 Ford LTD S 4 door soft top
I recently bought a 1979 Ford LTD S the two headlight version not the four headlight version it has 16K original miles which judging by all the original parts is an accurate statement I bought a New set of white walls and and some ford motor company Police dog dish hubcaps from the old LTD Crown Victoria Police car and for some reason my front left seems to kind of shimmy when I go over 40 which I'm a new driver I'm not a crazy man I don't go fast but my mechanic isn't sure what the problem is. So I was wondering because I can't find anything on it on the computer for that problem other than that its a great car and I think it was a 750 dollars to an old couple well spent.
Have tire balance rechecked. You didn't say what kind of tires were installed, but if a Chinese brand those tend to have quality problems that can be severe.
The front suspension components have had 43 years to deteriorate. Have it looked at by a chassis expert, it would not be a surprise if all the control arm bushings need to be replaced. Wheel bearings should also be checked.