here is more i came up with
The Six Pack package included more than just a unique intake and carburetor setup. Beefier connecting rods (and an appropriately weighted harmonic balancer), moly-filled top rings, a revised, low-taper camshaft, flat-face hydraulic tappets, chrome intake and exhaust valve stems with valve springs lifted from the Hemi and a bump in compression from 10.1:1 to 10.5:1 all helped boost the output of the 440 to 390hp and torque from 480-lb.ft. to 490-lb.ft, a number identical to that of the Hemi, but delivered a full 800 RPM sooner in the rev range. All A12s were also equipped with a 4.10:1 rear axle, along with a dual-breaker distributor, heavy-duty radiator, heavy-duty 11-inch drum brakes and "extra-fat" Goodyear 15-inch Polyglas red stripe tires.