Lee Thompson, head of Flowmaster's R&D shop, prototyped this B-Body system, and here he shows us how easily the new production 3-inch system is to install on header-equipped cars. Non-header-equipped engines need an extra custom-made head-pipe to complete the installation. It took Lee about two hours to remove the old system and finish-fit the new 3-inch stuff. The installation requires only a basic set of hand tools, although a Sawall is handy for the removal of the old system. When we installed the system, all of the pieces were first hung in place, without firmly tightening anything. This way, the system can be checked for symmetry while going on the car, and to make sure we had at least 31/44-inch clearance around all components. Taking the time to fit your exhaust like this will ensure the whole system is symmetrical or asymmetrical as needed, and the tailpipes emerge at the correct angle and extension from the rear of the car.

The new Delta Force B-Body 3-inch kit (PN 17382) comes with a full set of easy-to-follow, step-by-step instructions. Install the new hangers and clamps, set the mufflers in place, position the H-pipe, install the tailpipes, and then cut the header to intermediate pipe to length needed. Re-check all clearances, tighten the clamps, and do a final check of the system's alignment.

While the system can be held together with clamps, it can also be fully welded to give a nice, clean look. If you don't have a welder, you can fit the system at home, and then have a muffler shop do the installation, or just have them do the finish welding after you've done the fitment.

Once the R/T's system was in place, it was given a quick test-drive to check for leaks and rattles, and then put back to the chassis dyno. According to David, he could immediately hear the difference.

The sound was certainly more musclecar-esque, compared to the wispy, constricted tone the R/T had before. The Coronet was again brought up to temperature, and without any further tuning tweaks, the engine instantly ran stronger, pushing peak horsepower to 341 hp. That's an impressive increase of 52 hp, and peak torque was up to 403.7 lb-ft, an equally amazing 41 lb-ft. These are truly impressive numbers, considering the extent of simply reconfiguring the exhaust so the 440 could breathe correctly. According to Kevin McClelland, Flowmaster's dyno manager, this 440 could have easily added another a handful of horsepower with some simple carburetor and ignition work.

So, what did David Hoffman end up with? A great sounding R/T with a bunch of additional horsepower. After driving it for a day, David was still all smiles. Not only did the exhaust sound great, but it was perfect for the style of the car, and he could feel the engine's crisper and more aggressive performance. Please keep in mind, do not expect to get this kind of improvement if you are using cast-iron manifolds. According to Flowmaster, there will be a substantial increase in hp and torque numbers, but not as much as a good set of headers can produce.