12 We used a Sharpie to mark the fore-and-aft locations where the pipes were contacting the rocker moulding, then used a measuring tape and straightedge to lay out the vertical dimensions of where the moulding needed to be cut.
13 After marking the moulding, I used a wheelie cutter to rough in the clearance cuts. I then dressed the cut with a handheld grinding wheel so its radius loosely matched the curve of the pipes.
14 Once Tray Walden had checked the locations of the frame holes (to make sure they lined up with the mounting tabs on the sidepipes), I hit the holes with a disc sander to remove the paint around them and prepare them for welding.
15 Walden welds in the threaded inserts, giving the pipes’ mounting bolts an easy attachment point.
16 Once the inserts were welded into place, I ground the welds down close to the frame to give the mounting tabs a flat surface against which to lie. I then sprayed on some black paint to protect against corrosion.
17 Since the pipes tend to hang “downhill” once they’ve been slipped onto the collector, we used a jack at the rear to slowly raise them into the correct position. This allowed the mounting tabs to be bolted into place in the now-threaded frame holes.
18 Here’s the mounting tab bolted into place on the frame—note how the body interferes with the bolt head. Since a socket can’t fit on it in this position, this is open-ended-wrench territory. Remember, all of this will be covered by the rocker moulding once it’s reinstalled.
19 Once we knew where the pipes would sit when bolted in place, Walden welded the hole for the O2-sensor bung into the passenger-side pipe. While not usually needed for carbureted applications, this sensor is a must for an EFI motor that runs on a closed-loop system.
20 The O2-sensor bung is shown after welding. Once installed, the sensor should sit roughly horizontal. Note that it’s located behind the bulged end that slips over the collector. Any farther forward, and the collector would need to be cut as well.
21 While different computers require different setups, the FAST XFI system we’re using only needs one sensor (shown here screwed into place). It was supplied along with the computer and wiring harness.
22A Most side-mount headers are patterned after the OK Kustom pipes found on historic racers such as this one.
22B The aggressive, bundle-of-snakes look imparted by the four primary pipes is perfectly in keeping with the theme of our project.