incorrect,, there are long and short,, r and rb is deck height has nothing to do with length,,search a chrysler with a 413 you will see the longer length
Wrong again. The "shorts" were only available on the 413 (1960 400hp, all four speeds, 8 cars built; 1962 405hp; 63 all 300-J; optional 64 300-K). The "longs" were standard on the 1960 300-F and the only intake available on the 1961 300-G. The "longs" with the SAME casting number were available on "B" motors in Dodges and Plymouths (possibly DeSoto, too). They are the SAME PHYSICAL LENGTH.
BUT, when installed on an "RB" the overall width of the package is narrower since the head is farther to the other side of the car, effectively moving the entire ram to that side.