Help me decide on new exhaust for 73 Formula 400
 

Relatively stock setup. I'm expecting to stay with a 2 1/2" system.

There seems to a lot of choices. So many that I'm exhausted! haha

What are the pros and cons of a transverse system and/or the duals setup?

I went with the pypes 2 1/2 transv on my 74 - so far so good.

I like the extra ground clearance on these sh*tty roads.

One of my tips came out shorter than the other is my only gripe.

Buddy put flowmaster set in his 72 and he likes it.

I'm running doug's headers and flowmaster's 17104 transverse system on my 67. Here's a video I took so you can hear what how it sounds.

https://youtu.be/XyMRq8ne_WQ

We went with true duals using 14" Dynomax Super Turbos with the tips coming out behind the rear tires on our F Body 25 years ago.

System was tucked up nice and tight and the last 16" inches of pipe was done in stainless pipe for corrosion free exhaust tips.

The Super Turbos are relatively quiet while cruising, but loud enough for me at idle or when blipping the throttle. NO DRONE!

This is a Pypes 2-1/2" X-pipe transverse system.

350/413 stroker with Comp XE276HR cam and 6X-4 heads

https://www.youtube.com/watch?v=WEAOsbrju2U

No drone at all running down the highway with 3.23 gears.

The few extra dollars spent at a competent muffler-exhaust shop is money well spent. The car will be exactly right before you leave with it. Every pre-bent system I’ve ever purchased and installed required additional modifications to fit and look correct. As mentioned earlier 2-1/2 pipes with Dynomax 17734 Super Turbos is a drone free muscle car sound.

The only issue I have with muffler shops is it's nearly impossible to find one with a mandrel bend machine.

While some may not care, there are a few of us that look for performance advantages. So I got away from exhaust shops many many years ago.

Yes the kits on the market do require additional modifications to fit, that's just hot rodding, and honestly with as much that has changed on these cars over the years we can't hold these manufactures of kits responsible for exact fitment, that's just a little much to ask for.

I've installed literally dozens and dozens of kits over the years from at least 8-10 different manufactures on more models of different cars than I can count and they all need trimming and tweaking to some degree but in the end they fit and function as they should and the car never had to leave my shop.

As far as drone I've found that if you use factory hangers with these aftermarket systems the noise is isolated much better than the cheesey hangers that most kits come with. A good quality OEM hanger goes a long way in that area. From there muffler choice is your friend.

As far as differences between transverse and dual muffler systems, it depends on the car I'm working on. For F-bodies and X-bodies I prefer transverse systems. I can tuck the pipes up tight for a nice clean appearance to the point you can't even see an exhaust system under the car unless you're laying on the ground. Nice for these types of cars, especially when everyone is lowering them these days. I even grafted a 2 1/2" mandrel bent F-body transverse system on my sons H-body vega and tucked it all up to the point it can't be seen, works great on that little car, a car that the aftermarket doesn't support, so I made it work. I leave the dual muffler systems for the A-bodies. More room to work and even on a car that's designed for it the mufflers tucked up high are still slightly visible from the rear of the car.

It's just personal preference.

Just to show the non-mandrel bent tubing results here are some photos of a 2 1/4" tail pipe I recently replaced with mandrel bent tubing. I cut the tube mid bend and you can see the tube is now well under 2" ID. Turning the tape 90 degrees it measured barely under 2" ID

Just in the short tailpipe I replaced there were 4 of these necked down spots.