Gardner Exhaust 1972 Buick GS 2.5" performance exhaust system


When I first assembled my convertible, I went with a 2.5" mandrel bent system and Walker 17749 mufflers. While the system looked and sounded great it was also quite loud for my taste. I prefer quiet cars, these are restorations and being loud seems out of place. My mistake. It also gets annoying real fast. This is probably made worse by the downturned exhaust tips and being a convertible. I tried going with stocker cop car mufflers and while they did quiet the thing down, it was still too loud for my taste.

The crazy thing is my hardtop has an exhaust system bent up by a friend 20+ years ago, 2.25 pipes front and back with the normal restrictive bends and stock style mufflers and it sounds great. I didn't think 2.5" mandrel bent would be such a difference sound wise. Perhaps it is the engine build as well. The thing is I don't know anyone well enough up here to trust them with bending pipes up under my car, being so nice underneath.

So with that in mind I called Gardner Exhaust after hearing about their systems and even though I was not committed to buying, they were helpful and friendly and answered all my questions. After more looking around and talking to a few people, I called them back and ordered one of their performance systems. Their concours style systems are stock appearing right down to the restrictive bends, with 2.25" headpipes and 2.0" tailpipes, their own mufflers, and all hardware. You have your choice of natural or plated hardware. The performance systems are 2.5" headpipes and 2.25" tailpipes, also with their own mufflers, and all hardware.

I didn't want totally stock as 2" tailpipes would look silly under the car IMHO, and still trying to let the engine breath a bit.

The kit showed up in two big boxes, and the packaging was excellent. Each pipe was inside a plastic cover and the ends had foam caps on the ends. The mufflers were in their own boxes, inside another box with the hardware included as well. It also came with instructions for the kit, a copy of the original assembly manual diagram, feedback form with pre stamped envelope and also a Gardner Exhaust drinking glass. Parts had labels on them so there is no way to screw it up, they even tell the orientation of each part (pass side, fwd, up). Once in place the labels peel off very easily. WOW!

The system went on quickly, everything lined up perfectly and was simply clamped into place as per the directions. It looks completely stock. It should, they use factory GM blueprints to build the systems.

The sound is perfect. The car is quiet with just a nice tone around idle you can tell it's a big engine but not obnoxious, and once you hit about 45-50 mph the car just goes silent. It's pretty amazing actually, you can't hardly hear the exhaust at all even with the top down above that speed. The amazing thing to me was how much more fun the car is to drive. I didn't notice a difference in power, yet it takes much less noise to get the same result. I suppose in a world of imports with 4" fartpipes and Harleys setting off alarms that might seem kind of odd to many people, but to me its perfect...I'd rather let my tires do the talking!

In 1972 from the documentation I have (Dec 71 dated parts catalog, assembly manuals) it appears both the 350 and 455 cars got the same mufflers, which are the flat oval style p/n 1240263. 1970 and 71 had different part number mufflers for small and big block cars, not sure on exact shape of those mufflers. So that and the double cut tips make 1972 (once again) a bit of changeover year.

No pictures except installed. Sorry about that, I was so excited to put this on the car I totally forgot about documenting anything... :)


Idle in gear video

Sorry about the jet overhead.


Walkaround video


At Speed video

Note that there was a storm blowing in, you can see it in the trees and hear the wind buffeting, the 4" dash speaker comes through clear since recorder is right over it but you can not hear the exhaust.Top is down.




Drivers side manifold attach point.


Looking forward. Even with only 600 miles on the car there is already dirt and the occasional water splash on the bottom. Also note no names and correct shape of mufflers. One of the nicest things about this system is that the headpipes are one piece...most systems are designed for headers so if you use downpipes you end up with a clamp or a weld right under the tranny crossmember. You can't see it but Gardner puts the flat spot in the top of the pipes where they pass under the crossmember. Camera flash washed everything out badly so this was taken without a flash, 35 second exposure.


Tailpipe and hanger. Mud is from turning the car around in the alley.


Only original shot I have, those are the original date coded p/n 1240263 mufflers.



Close up of the double cut tip on the 72 cars. 70 and 71 had the flush cut tip prallel with the ground. Check out the rock in the tire just waiting for a good time to fly out! :)


Gardner Exhaust Systems



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