For originality the 283 is the way to stay. 350 do have more power but chew up more gas. The 283 can get depending on gearing 17-20 hwy. 350s, I have one, get about 13-16 usually. Sometimes a bit more sometimes less. My pick up got 11.5 city with auto and FI. Had good power but thirsty. Got just over 14 hwy. Not very good. Once got 17 with the timing far advanced which is not good to do. Takes out the rod bearings sooner. My first car was a 61 Chevy Bel Air with the 283 auto. Ran awesome. I wish I had that today in the shape I got it in. It was 4 door with red and white colors. Ran smooth. Used no oil. I would do a rebuild on yours with some headwork and MSD ignition, balancing, dual 2 1/2 inch or 3 inch exhaust, headers with 9:1 pistons. Should run awesone and get good mileage. Remember, WHEN we go to war with Iran, gas at these prices with seem like a bargain! Something to think about. A nice sweet stovebolt 6 is something to consider. They can be made to run quite well with some work. In 65 they had a 230 or a 292 inline. The 250 came out in 66'. Just a few thoughts. I'd rather drive mine daily or at least often then just once a month or so and the rest of the time just look at it due to high gas prices. A 350 or big block for speed or an inline stovebolt or 283 for economy. Even a 327 2bbl didn't do too bad on fuel depending on set up. I love the stovebolts purrrrrr.
