hello all. i am lucky enough to own a pretty great 71 deville with the original 472 engine in it. great motor, runs well and sounds awesome, only problem is one i'm sure most of you can sympathize with.....gas millage. i'm getting 4 mpg in the city, 10-11 mpg hwy. not very practical for a daily driver, which i would love this car to be. i'm looking for recommendations on what a good replacement motor might be, something more modern, maybe fuel injected, that might get me 11-15 mpg city 20-25 mpg hwy. any suggestions? in the past folks have recommended ls1, but they seem a bit pricey. i myself have wondered if a 4.9 might work, as i have enjoyed the performance of those in the past. any thoughts?