Allpar had this to say:
Of the Golden Lion 383 perhaps there hasn't been as much divisive condemnation of that engine due to its simultaneous introduction of its bored out big brother 413.
The 383 "RB" (Chrysler) had its head deck raised, and was stroked to the famous (or infamous) 3.75 inches that covered the RB 383, the 413, the 426, and with the thin wall casting techniques, the 440. It was also the same size stroke for the 426 "HEMI."
In the "RB" family, the outward appearance will not give you a clue as to the cubic inch size. The major difference is the bore size. The 383 was a 4.03 inch bore. The 413 saw a 4.18 inch hole which directly resulted in an easy leap to the NASCAR limit of 426 cubic inches by boring the block to a 4.25 inch diameter. It was about the limit for this block.
P.G.