Back in the "day", I had a '56 210/2 dr. with a 265, .030-.030 Duntov cam, vette 2x4's, 4:56's and overdrive. The '56 weighed 3000 lbs. and it ran like jack-the-bear. It would also get over 20 mpg. I am contemplating taking my extra 305 block and finding a 3" crank and building a "late" model 265. I'll use a tuned port and World Products heads and a hyd. roller. A 283 in '57 would make 1 H.P. per c.i. and that should be no problem with all the new products out there now.
As several members have written, there is no substitute for cubic inches and a big motor will make more h.p., also the car you are putting it in will make the decision easy, heavy car-big motor, lite car-little motor.
Build the 283 if it's 3000 lbs. or less and have a blast trying to convince everyone it's "only" a 283.
Jim