Best Mufflers for 1970 GTO RAIII - Pontiac GTO Forum
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post #1 of 2 (permalink) Old 06-26-2017, 07:14 PM Thread Starter
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Best Mufflers for 1970 GTO RAIII

One of my mufflers started rattling. So what do most of you favor as far as replacement mufflers and series number. I am leaning towards the Flowmaster 40, but I don't want it to much louder than stock. The exhaust is the stock 2 1/4" configuration. Thanks for your opinions/input.
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post #2 of 2 (permalink) Old 06-26-2017, 11:10 PM
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Would suggest a long case Walker Dynomax muffler with a center/side configuration & 2 1/4" inlet outlet. Very hard to beat, performance wise, I've run that particular muffler as well as the old Walker CVX version, which is basically the same muffler.

If you are eventully planning on going with mandrel bent down tubes & 2.5" headpipes, then Id go with the Dynomax 17749's & then come out of them with the 2 .25" tailpipe . They are the same long case configuration just with 2.5" inlet & outlets. The full length Dynomax mufflers flow better & aren't near as obnoxious as the 40 series Flows. Have cut quite a few 40 series box mufflers off friends Pontiacs, quite a few 90's throttle bodied GM pickups around here still run the noisy box mufflers.
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