The ‘B’ engine was developed as a replacement for the EarlyHemi engine for use in the big cars of the day. The ‘B’ designation simply followed the established ‘A’, and when a longer stroke version was designed for 1959 it was simply a (R)aised deck ‘B’ engine…RB.
The B-RB engines include the following displacements:
B Series
350 (This is the original wedge engine, 1958)
361
383
400
RB Series
383 (Yes, a long stroke 383, 1959, Golden Lion)
413
426
440