any advice on how to make a 3½" exhaust liveable on the street? would be nice being able to drive to the track without atracting every policecar in the country and being able to hear something else than a ringing sound in my ears when i get to the track
would some 8x5x18" straight tru mufflers be anywhere close to quiet enough?
i would like to avoid a x-pipe since im sick of that sound, maybe a h-pipe

I had 3" on my smallblock w/straight thru mufflers. Way loud in the car, and outside as well. Twenty minutes in the car and a raging head-
ache. Changed them out for more conventional
mufflers. Tail pipes maybe next.

I have a three inch system on my car(no X or H pipe) that uses a set of Magnaflow 3x14 oval muffs mounted at the rear bumper, not noisy until wide open throttle . The motor is a 518 C.I. low deck pump stroker motor that runs 10:30 in the 1/4 at or above 128 MPH with the exhaust system on the car runs .04 ET faster in the 1/8 mile with the exhaust off compared to with it on, not worth taking it off I have not tried removing it at a 1/4 mile track so I don't really know how much better it would run in the 1/4 I had originally planned on having a 3.5 inch system installed on the car but the muffler shop forgot to order the 3.5 muffs and mandrel bends to do the job, I was moving and in a hurry so I let them use the three inch parts, no real gripes now

Not trying to be a wiseguy 1fast340 but do you think you really need a 3-1/2 inch system on a 340! The larger the exhaust the louder it is. I think you could easily get away with a 3 in. system with a set of Magnaflows that would be streetable and loose very little ET at the track! It would also be much easier to install and you could run it out the back past the bumper!
Mike

I agree that`s maybe a bit too much but, what do I know.I do however run a 3 1/2" exhaust w/bullets which is loud but so far no unwanted cop attention.

My brother has a 3.5" x-pipe and hooker aero chambers on his car and it's pretty darn loud imo. It also hangs low because of the bigger diameter so you have to pay more attention over speedbumps ect.

I think a 3" setup would be fine for a smallblock and if you ran it out the rear of the car would quiet it down enough to stay out of trouble.

I run 3.5" pipes with 3.5" 'PYPES' brand Race Pro mufflers, stainless steel for $75 each. They are not LOUD and run just like open headers at the track, I love them. I've also ran Magnaflows with the same results but they're $110 each.

My motorhome is 3" exhaust, and it's fairly QUIET.
It has two Flowmaster 50 series mufflers.

1 3/4" headers go into 2 1/2" collectors. the two headpipes merge, and Y into a single 3" exhaust. Two Flowmaster 3" 50 series run in tandem, one after the other, then out the back.
It's quiet, and I lovvve the sound.

I went with four mufflers on my Jensen, two large turbo mufflers into two Dynomax Bullets. Couldn't be happier.

I like mufflers run in tandem I guess....?

This is 3-1/2" on an A-Body. These Mufflers are super quiet and did not slow down my Demon one bit when I put them on it. 3-1/2" all the way including the full "H" and a tapered cone down to a 3" in and out muffler.

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3

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3" with an H-pipe on my 63 street car. I use 1-3/4 headers that go to a 3" collector. Then into the H-pipe to Dyno-Max Ultra-Flow mufflers. Its not as loud as you would think. My sons 3" system on his Dart is louder with the Flow Master's. I always race thru the pipes as I never uncap it. I would think 3-1/2 would be fine if you run all the way out the back and use good mufflers. Ron

gues it may end up alitle loud then
reason i would like it in 3½" is that there is a plan for a much more powerfull smallinch motor in just a few years time and this screwblown little 340 is just a step on my way so i get to drive this car alitle and learn alitle more about blown motors before i build a bad to the bones gen3 HEMI and im not all that bad at building exhaust for myself but i realy dont want to redo it more times than i have to..
i dont think 3½" to the back of the car would be a big problem since i run a fuelcell inside the car and the sparetire well has been replaced with flat sheetmetal, but it may be alitle frustrating with groundclearance

thanks for the pics and advice it dont look to bad actualy

Nice setup

i run 3.5s, with a 3.5 cross pipe, walker welded ultraflo welded oval straight through "mufflers", and turndowns. at cruise they are surprisingly quiet. at wide open throttle they are alarming! with tailpipes, they would probably sound almost normal, at light throttle, anyway. an hour is about the longest i can take w/o earplugs.