Is a 383 engine hemi?

Not necessarily. A 383 cubic inch engine is a displacement size, not an engine type. While many 383 engines were Hemi's (specifically the Chrysler 383 Hemi in the late 50s and early 60s), many others were not. Plenty of 383 engines were built with wedge-shaped combustion chambers, not the hemispherical shape that defines a true Hemi.