383 vs 360 in an A 68 Cuda

My opinion only! Unless it came with a 383 from the factory, I wouldn't bother swapping in a 383 when a 408 is bigger, lighter, fits better, and can make equivalent power. I WOULD swap in a stroker 440, or better yet, a stroker 400, if real power is desired. That's what I plan for my 67 barracuda.