I will let Gene speak for himself when he sees this but I think he put Magnaflow mufflers on... or at least at one point in time he had them on but may have changed them.
I also have these on my 67 but I put on Stainless Steel units. I looked at Genes exhaust system at Chevelleabration and his mufflers (not stainless) were much longer than my style. Mine are only about 15-16" long (going from memeory) and give off a very deep throaty sound until you put your foot into it, then it has a loud crackling sound. This is from a stock 396/350HP motor with Dynomax headers into 3" pipes and 2.5" tail pipes. In my opinion,a lot of the sound variation from car to car has to do with Compression ratio & pipe size and not just mufflers. My recollection as Gene hammered it down the 1/8 mile Friday night was that his car is quieter than mine and sounded significantly different even though he has a much helathier motor than mine. In this case, I think the size of his muffler is the difference assuming he is still using Magnaflow technology.
One other point, at the time I got mine, Magnaflow could only be purchased through Muffler shops. This may have changed.
Robert, well said. I read here that 22" cases are the largest muffler you can fit on a Chevelle. So I had a local installer order up a pair of Magnaflow #12578's. It is MUCH quieter than the 2 chambered one I had ( which were less than 12" in case length).
The exhaust was quite radical before, as one might imagine with 3.5" headpipes/X pipe and mufflers that look like they go on a go-kart. Now its a sleeper!
Lonnie, they look very well constructed and although I was told they wouldnt compact like Dynomax's and get louder, they did a bit.
Magnaflows, thats it, I couldn't remember the name.
I agree that the same muffler sounds a lot different from car to car with different HP. I have to get rid of these 40 series deltaflow Flowmasters. Very loud at idle, and full throttle you can hear me for miles.
It is the 2.5" kit with h pipe and tails. I like the way it sounds but it is way too loud.
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