Old Anvil Speed Shop’s Streamlined Solution for Replacing the ’48 Chevy’s Ugly Exhaust!

By Rob Fortier   –   Photography by Taylor Kempkes

Back in October of last year I made arrangements with Paul Bosserman, my friend who just happens to own the family run Old Anvil Speed Shop in my old stomping grounds of Orange, California, to do a “couple” things on my then-dormant ’48 Chevy project. (I’d acquired the chopped ’n’ bagged three-window over a year prior. Due to its needing way more than advertised to put it back on the road, I chose to throw a cover over it … ’til now.)

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02 Close up of a classic truck's transmission and exhaust system

Read More: Building a Granatelli Motor Sports 3-Inch Stainless Steel Oval Tubing Exhaust

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Bosserman was kind enough to agree to install a new Air Lift/FLO Airride management system (to replace the cool but antiquated MIC-style manual valves) initially, but after a conversation at the Grand National Truck Show in September, that list grew to include a BedWood & Parts curly maple wood floor with a Legen’s Hot Rod Shop hinged center plank—in conjunction with Old Anvil’s still-in-development All Access VIP hinged bed floor frame kit. But that was it—that’s all we agreed upon! That is, until Bosserman and his trusty sidekick, Jake Caballero, started tearing into the truck.

03 Exhaust piping under a classic Chevrolet truck with wooden support

Not a week after dropping the ’48 off, I get a text from Bosserman: “I’m replacing your exhaust … it sucks.” I’m not certain if that was before or after we’d discussed the brakes (now being upgraded with a Wilwood remote-fill master), the steering (now being upgraded with a new Borgeson stainless linkage), and the battery situation (already upgraded with dual XS Power AGMs), but I do clearly recall getting that text!

04 Mechanic's hands installing exhaust pipes on a vintage truck

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Long story short, and multiple to-dos added to the list later, we agreed to replace the rusted-out dual exhaust with a nice, TIG-welded stainless system—I just needed to procure some accommodating mufflers. A not-so-impromptu meeting with my buddy Joe from Speedway Motors at the SEMA Show took care of that last part (in the form of polished Porter “sound deadeners” as well as flanges to complement the Speedway Tru-Ram stainless headers already in use); Old Anvil would handle the mounting via their own custom-made hangers. The rest, as they say, is “his” story … so, take it away, Caballero!

05 Installing a curved exhaust pipe on a classic Chevrolet truck

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“When the truck came in it needed some exhaust work done. We came to the decision to replace it completely. First, we started by removing the old worn-out exhaust because it had been repaired a couple of times and would be more work to fix it than to just build a completely new system. A saw was used to cut the old system out. The frame was then cleaned up by removing all the old tabs and hangers. We began the new system with laser-cut header flanges and 18-inch polished Porter mufflers all from Speedway. All of our 2 1/2-inch tubing was from Ace Race Parts, while our exhaust hangers are laser cut and sold at Old Anvil Speed Shop.

06 Alignment of exhaust components beneath a vintage truck

“When building an exhaust, I like to try to make maintenance as easy as possible, like clearing the oil filter and starter. First a couple of bends are held up at the collector to get the angle needed to get around the oil filter and the starter, then a couple of straight sections are tacked into place. Next, two 90-degree bends are tacked together and fitted to offset the exhaust over the crossmember. From there, two short straight sections were tacked on to get to the flex couplers. The flex couplers absorb all the vibration of the motor to prevent cracking—we rigid mount our exhaust systems so there is no need for rubber bushings that could wear out over time. Next, we tack on our V-band clamps after the flex coupler. A rigid mount is now placed behind the flex coupler and before the muffler, that way the weight of the muffler is not hanging on the flex coupler. After our V-bands, a straight section or tubing tacked in place and the stainless mufflers can be tacked in.

07 Close up of exhaust pipe assembly on a classic Chevrolet truck

“After the mufflers we had to make a decision where the exhaust needs to exit. Going over the rearend like most cars was going to be difficult because of the large fuel cell and the airbags, so we went under the rearend. Two bends were once again tacked together to make an offset to get under the differential. Now the exhaust turns and goes up toward the framerail, from there one more bend is tacked to angle down to the tip. We like to get the shallowest angle possible so the exhaust flows out from under the truck rather than straight toward the ground, so you don’t blow up a lot of dust and dirt. Once everything was finalized, I made a rear mount but did not weld it in yet. I like to fully weld the exhaust out because it tends to distort from welding and will never go back in the same place you had it. Once the exhaust was fully welded out, the front and rear mounts are welded on.”

08 Metallic exhaust bend parts and tools on a workshop table

When all was said and done, not only did I have a beyond aesthetically pleasing to the eye exhaust system (which was one of Bosserman’s main objectives seeing as the forthcoming All Access VIP bed floor kit will be “all revealing,” if you know what I mean), I now have an audibly pleasing to the ear—in a mean, non-sissy, twice-pipe kinda way—full stainless exhaust system! Now onto the rest of that to-do list before Old Anvil finds anything else wrong!

09 Measuring exhaust pipe dimensions with a ruler on a workbench 10 Cutting metal exhaust piping for a classic truck restoration 11 Craftsman cutting metal with a bandsaw in a workshop 12 Close up of a metal pipe's edge after being cut 13 Freshly cut metal exhaust pipe being inspected 14 Holding a metal pipe with a deburred edge 15 Grinding a metal pipe on a workshop grinding wheel 16 Close up view of a polished metal pipe in a workshop 17 Sanding the edge of a metal exhaust pipe on a belt sander 18 Detailing a metal pipe with a pneumatic angle die grinder 19 Craftsman precisely measuring an exhaust pipe bend with a caliper 20 Shiny metal pipe with smooth rounded edge after fabrication 21 Close up of weld points marked on an exhaust pipe 22 Mechanic fitting an exhaust pipe on a lifted vintage truck 23 Attaching flexible exhaust coupling to a vintage truck's system 24 TIG welding on an aluminum exhaust component 25 Operating an industrial metal bandsaw with a long metal pipe 26 Cutting a metal exhaust pipe on a bandsaw in a fabrication shop 27 A mechanic preparing to weld a metal pipe 28 Mechanic adjusting exhaust pipe under a vintage truck on a lift 29 Mechanic securing an exhaust component under a lifted truck 30 Mechanic aligning an exhaust pipe on a classic truck 31 Mechanic installing a tailpipe on a vintage truck 32 Bandsaw cutting through a stainless steel exhaust pipe 33 Hand positioning an exhaust pipe for fitting under a classic truck 34 Welding a flex pipe onto an exhaust system in a workshop 35 TIG welding an exhaust component focused on the welding arc 36 Final installation of dual exhaust pipes under a vintage truck 37 Close up of the dual exhaust system installed under a classic truck 38 Welding a flexible exhaust section onto a pipe 39 Overview of a custom dual exhaust system on a lifted vintage truck


Old Anvil Speed Shop
(657) 223-9889

Speedway Motors
(855) 313-9176

Click on this issue’s cover to see the enhanced digital version of Old Anvil Speed Shop’s Streamlined Solution for Replacing the ’48 Chevy’s Ugly Exhaust!.ctp april 2024

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