I have a 1973 LeSabre Luxus with the 455 four barrel, it's a four door body with posts. I got the car at an auction and do not know anything about its history, but it is obviously a low miler (87 K on the clock), in very good shape. It uses about a quart of oil every 600 miles, but no smoke and no oily residues in the exhaust pipe. It is strong but not spectacularly so, idles nice, but a cold blooded starter. The air pump has been removed and the holes in the manifolds have been plugged with threaded pipe plugs. Mileage is not great, about 10 mpg city, 15 to 18 highway (I have a bit of a leadfoot, but even when trying mileage is still high). My questions are, should I be concerned about the oil consumption (seals maybe?), and can I improve performance AND mileage by retrofitting pre 73 components (like cams, heads, etc.). I also don't like the spongy handling, the shocks are good, but when I turn, it seems like the wheels are going one way and the body is heading in the opposite direction. It works best on the interstate, nice smooth highway ride, but I mostly drive around town.
