The 1961 Chrysler 300 J
For 1963, Chrysler dropped the convertible letter series version, leaving the new 300 J hardtop (there was no 300 I - perhaps they felt the "I" would be confused with "1"). The standard engine offered was the 413 cid wedge head V8 with "short" long rams which was now rated at 390 bhp. The “short” rams were divided internally only halfway which raised the torque peak from the 2800 rpm peak in the 1960-61 style fully divided long rams to 3600 rpm. This change provided spectacular high rpm performance in the 300 J. Also, the suspension was softened very slightly from 300 H specs, but was still substantially stiffer than other Chryslers.