From a 318? you gotta be kidding a 383 is a leap over a 390 stroker.
With the right head a 383 is a very formidable engine.
It depends what ya want to do.
I think 383/400 are perfect displacement for the 450-550 hp range puts peak hp rpm in the street strip range of 5500-6500 rpm depending on power, Plus got bore sizes that will allow the heads to breath well at those hp/rpms.