431 Engine Build - Build A Bigger B

During launches, we noticed the slicks would unload and slip at about 10-15 feet out of the hole. Having tested (strip and skidpad) the QA1s before, we knew we could lower e.t.'s even further. The antiquated load-leveler shocks (rear) were installed in the late '80s. In the front were 5-year-old KYBs. Now, we would remove and replace them with the QA1s. The rear QA1s are a 12-way adjustable 50/50 (compression/extension) shock. The stiffness can be easily adjusted by turning the knob on the shock. On the front, the QA1s are 90/10s when setting the knob at zero clicks. The fronts change the valve ratio on each click and become regular 50/50 shocks when set on the max 12-clicks setting.

After setting the front QA1s on zero and the rears on 6 clicks, we pulled the Bad B to the line. During the holeshot, we watched how the rear tires stayed planted to the pavement with no spin. Looking at the clocks, we noticed an improved 1.64 60-foot with an 11.73 at 114.39 mph. Our routine backup pass showed us a consistent 1.64 60-foot and 11.74 e.t. The Coronet was hooking to the track like glue! We pulled a spark plug to check our tune. The plug looked clean (very light tan). Now with a great hook, we knew a set of bigger carburetor squirters would lower the 60-foots a bit more. TorqueFlite-equipped cars with a loose converter (2,800-plus stall) usually respond to this trick. And respond it did with the 60-foot and 1320 times dropping to a 1.62 and 11.72. We gave the Coronet a solid half-hour cool down, hoping its last pass would be its best. The cool down worked out to our liking. The 431 Dodge was really diggin', and posted a best 1.61 60-foot and 11.71 at 114.52 mph.

There are mountains of extra torque; the throttle response is instantaneous; and driveability is as good as before-better, actually, because gone are the exhaust leaks from the antique Magnum exhaust manifolds. Now the owner's got a legitimate 11-second driver musclecar-that's a claim that not even some Street Hemi guys can make.

Dyno ResultsTested at Crazy Horse RacingBaseline 383Peak rwhp: 281.0 at 5,600 rpmsPeak rwtq: 331.9 at 3,600 rpms

Muscle Motors 431Peak rwhp: 382.9 at 6,000 rpmsPeak rwtq: 465.1 at 3,800 rpmsPeak gains: 101.9 rwhp and 133.2 rwtqNote: At 6,300 rpm, the 431 was making 140 more rwhp than before. That's the TorqueFlite's shift point.

Strip Test ResultsBaseline 383Temp: 58 degrees; humidity: 51 pecent; barometer: 30.12Car and driver pounds: 3,885