$2800 would be great if it had a small block in it. Not that you couldn't put on in easily enough. Different engine mounts, suspension should be OK, make sure the transmission bellhousing is the same, or that can be changed easily enough too. The key here is as mentioned by another poster, get it on a lift and check it over really closely for hidden rust. Be wary if it is heavily undercoated by black tar like stuff. Sure that inhibits rust, but it also hides it. Finding out the car is in bad shape when the spring comes through the trunk is not a good thing. Your vision of this car is not likely the same as mine anyway since you are looking for 50mpg. I measure my cars in 1/4 mile times, not gas mileage. New tires are only good if they are the tires you want for the car (speed rating, size, style, etc). Check out the electronics carefully to make sure everything works. New wiring sounds great unless it is installed by someone that is not 100% sure what they are doing. I'm assuming this is a two door car too because those Novas in four door configuration just aint real appealing...