The SSBC kit comes with a front disc/rear drum master cylinder. We purchased new rear wheel cylinders but not brake shoes. Installing new shoes would have skewed our braking distance results. Comparing the difference in performance front disc versus humdrum front brakes was the real importance of this test. Eastwood's Diamond Clear will protect all of our bare metal and cast parts for years. | 
During our baseline brake testing with the drum brakes, we encountered scary rear brake lock-up. In an effort to reduce lock-up, we tried new wheel cylinders with smaller 7/8-inch pistons (stock was 15/16-inch). Most auto parts stores list the 7/8-inch wheel cylinder application for a '77 Dodge D-100 pickup. They are a bolt-on part that fit the '60s and '70s B-Bodies. |
After completing the buildup, we decided the stock replacement 9/16-inch tie-rod ends and split adjusting sleeves wouldn't hold an alignment with the other "stronger than stock" parts. We again called Just Suspension for their heavy-duty 11/16-inch tie-rod ends and sleeve kit (PN HDTRE1116S). | |
Test For Whoa
Before we got into the front suspension and disc brake install, the 11-inch drum brakes received a series of 60-mph stops, both cold and hot. The drums showed us a best 60-to-0 stop of 168 feet (cold), with backup stops (hot) fading to a frightening 230 feet achieved during our third stop test. As the R/T progressively became faster, the drum brakes had limited ability to safely haul us down from the higher trap speeds-especially when hot.
The R/T was brought to our friends at Shore Wheels in Tuckerton, New Jersey, for a front-end alignment. The Shore Wheel guys dialed-in a touch of negative camber (-0.70) and positive caster (+2.5). This will help the Coronet drive and handle better than if we received a stock specification type of alignment. | 
Up front for skidpad testing, we wanted to see how the track width and tire contact patch would affect the lateral-G numbers. Here the 215/75R -14 Coker Redline shows its scuffed sidewall after some laps. From Summit, we ordered the 15x7 Weld's with 3-inch backspacing (4 inch is standard) and 235/60 T/A's to widen the track 3 inches, while the tire contact patch was increased 2 inches. We set the QA1's at 10 clicks. |
In the rear, we employed the same size (225/75R-14), Coker Redlines mounted on wider 14x7 Magnum 500s. The 14x7 Magnum 500/ radial Redline combo increased track width by 1 inch over the original baseline. The stickier and wider Nitto rear meats (275/60R-15) on the 15x8 Welds were performing double-duty (strip and skidpad testing) and did so quite effectively. The Nitto/weld combo increased track width 3 inches from stock. The rear QA1's were also set at 10 clicks. | |
On the day of skidpad testing, we made back-to-back, 11-second, quarter-mile passes without any evidence of brake fade. Out in the Pine Barrens, the 60-to-0 panic stops were knocked down to 152-155 feet (from 168 feet cold, 230 feet hot). Unfortunately, we still experienced rear brake lock-up and scary swerving. Once back home, the adjustable proportioning valve (included in the kit) was installed for safety's sake. After the valve was adjusted to banish lock-up, stopping distance was reduced to a repeatable 140-142 feet without any signs of fade. All brake testing (drum versus disc) was performed on six-year-old Coker tires. Braking distance could have been further decreased if we switched over to the wider tire/lighter wheel combo. Once testing was complete, the flat-spotted tires were replaced with a new set of Coker Radial Redlines for our red R/T.
After testing, we felt too much braking effort was required during stop and go traffic, or when the motor was cold or idling too long. This was due to the big cam (575 lift, 262-degrees duration at .050-inch). For fearless braking at all times, we opted for an electric vacuum pump from SSBC. Vacuum pumps also add an extra safety margin. If the engine stalls, the pump will still pull vacuum to the brake booster.