1957 Chevy Bel Air - Dual Exhaust System

Did you know that not all '57 Chevys are the same? Let me explain, lest you think I just fell off the turnip truck. According to the install sheet on our Flowmaster instructions, the platform for the '57 Chevy was available in two different versions and from six different plants around the U.S. and Canada ... eh. That would make quite a few '57s that are slightly different from one to the next.

Now it's 50 years later and those '57s may have (and probably should have) had altered suspensions, height changes, big-block swaps, etc., thus furthering the mutation effect of the chassis. Imagine trying to engineer a one-size-fits-all exhaust system for this type of platform. Imagine no more. Flowmaster has recently hit the market with a complete "one-size-fits-all" '57 Chevy exhaust system called American Thunder.

1957 Chevy Bel Air Flowmaster Exhaust System

For all the rubber-neckers out there, here's a shot of the 2 1/2-inch U-Fit Dual Kit, with the Super 40 Series muffler.

For all the rubber-neckers out there, here's a shot of the 2 1/2-inch U-Fit Dual Kit, with

Jason Scudellari (our Primedia Tech Center guru) does quite a bit of wrenching for many magazine titles, so we asked him just how good this Flowmaster "bolt-on" system was. He responded, "I was very pleased at how it went in. Only a couple of minor issues came up."

Jason informed us that he had to bridge the gap between the header collectors and the start of the exhaust with a lead-in pipe. That's to be expected owing to the varied amount of header manufacturers and header lengths on the market.

That's pretty good news for those who have a stock-styled '57. But what about the guy who has power-packed his '57 with a 572 big-block or an LS-based engine? Or the person who has an aftermarket IFS rear or front clip under his '57? Lions and tigers and bears, oh my, where do the variations end? Flowmaster has an affordable answer for that problem too. Known simply as the U-Fit Dual kit, this universal system will conquer the unknown exhaust issues that an altered vehicle may present. We'll spend most of this article following the install of the U-Fit Dual kit, since it's the more difficult of the two to tackle.

This particular kit does not come with exhaust hangers or mounting hardware. They can be ordered separately from Flowmaster.
This particular kit does not come with exhaust hangers or mounting hardware. They can be o
These headers were used on both '57 Chevys. Doug's Headers has an established history of making high quality headers that not only increase horsepower, but look good, too. The Tri-Y headers (as they are called) are ceramic coated and designed to fit most Tri-Five Bel Airs.
These headers were used on both '57 Chevys. Doug's Headers has an established history of m
After installing the Tri-Y headers, the lead pipe from the collector had to be modified in order to fit the exhaust as tightly as it needed to be.
After installing the Tri-Y headers, the lead pipe from the collector had to be modified in

The first half of the install from the collectors to the mufflers is the easier part of the job. The cut pipe is butt-joined and tacked into place. The welds will be finished a bit later.
The first half of the install from the collectors to the mufflers is the easier part of th
The exhaust pipes are tucked in tight against the body of the vehicle and don't hang below the frame. There's nothing worse than seeing an exhaust system that hangs too low. As the pipes are being fit and welded, Jason makes sure that they are always level and propped into place.
The exhaust pipes are tucked in tight against the body of the vehicle and don't hang below
Just after the transmission (right about where the crossmember is) is a good location to place the H-pipe. This too will have to be measured, cut and welded into place.
Just after the transmission (right about where the crossmember is) is a good location to p

So far so good. The H-pipe is in place and the mufflers are coming next.
Perhaps the best part of this particular system is the fact that the pipes are already flared, including the inlet and outlet of the mufflers. We don't have a pipe bender or flaring tool in the Primedia Tech Center, but one was not needed during this install. It can all be done with careful measuring, cutting and welding.
Perhaps the best part of this particular system is the fact that the pipes are already fla
With both mufflers being held in place with stands, they're tacked into place.

Before we went any further, the exhaust system was unbolted from the headers and the tack welds were welded in and filled. After it was completely welded, we reinstalled it and were ready to attach the brackets to the rear of the mufflers. Up until this point the install has gone fairly smooth-time consuming, but smooth. The last half from the mufflers to the tailpipes seemed to require the most cutting and test fitting.
Before we went any further, the exhaust system was unbolted from the headers and the tack
With everything back in place and supported, it's time to add the exhaust brackets. Drill into the support brace, and then thread the hole with a tap and die set. After this is done and the exhaust is hung, the support stands holding it all up can finally be moved.
With everything back in place and supported, it's time to add the exhaust brackets. Drill
It's at this point in the install where it can get a little difficult. This is how the Flowmaster pipe looks as it came out of the box. It should clear most axles, but we wanted our install as tight and close to the frame as possible. That means we had to change the geometry on it. You may notice the difference between the left side and the right. The right side has already been cut and installed, while the left side is still uncut and can hang below the leaf springs. We don't want that, so it's time to do some more measuring and cutting.
It's at this point in the install where it can get a little difficult. This is how the Flo

After the mufflers are hung and clamped, this is the last of the straight pipe to be installed.
After the mufflers are hung and clamped, this is the last of the straight pipe to be insta
After the cut, everything is tacked into place, then checked and rechecked to make sure it will all work.
After the cut, everything is tacked into place, then checked and rechecked to make sure it
We won't put you to sleep by documenting every cut and weld that goes into a custom-fit exhaust. After we are satisfied with the geometry and the angle of the dangle, the last and final straight piece is added.
We won't put you to sleep by documenting every cut and weld that goes into a custom-fit ex

And just like we did with the mufflers, the vehicle support brace is drilled and tapped in order to hang the exhaust brackets.
And just like we did with the mufflers, the vehicle support brace is drilled and tapped in
We didn't have any exhaust tips to add, but will put some on later. Take a look at how even both pipes look as they exit out from under the bumper. The extra effort it took to get that tight fit paid of in the end.
We didn't have any exhaust tips to add, but will put some on later. Take a look at how eve
Success! The bracket is bent to hold the last section of pipe and welded-and we are done like dinner. That wasn't so hard, was it? Well, it wasn't a complete walk in the park. But if you notice, we didn't bend or flare one piece of pipe. What does that mean? If you really want to save some bucks, you can do this at home provided you have all the right tools and time at your disposal.
Success! The bracket is bent to hold the last section of pipe and welded-and we are done l