383 due to it's shorter stroke is hard to build decent compression, the chamber volume on big block heads are a better fit for the longer strokes....
With a 383 a true 9.5-10 to 1 C/R either requires a domed piston or allot of milling off the heads...
A 440 on the other hand a flat top close to zero deck, a .040 head gasket & a 915 head puts you at 10.2-1 with perfect quench...