Highboy Mufflers

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Feb 17, 2016 | 12:51 PM

Highboy74

Thread Starter

Tuned

Joined: Jan 2010

Posts: 470

Likes: 9

From: San Diego, CA

Highboy Mufflers

What mufflers fit best under a Highboy? I was looking into the Magnaflow Round mufflers. They 20 inches over all length and 4 inches in diameter? What are your experiences or thoughts?

Feb 17, 2016 | 01:14 PM

HIO Silver

Fleet Owner

Joined: Dec 2009

Posts: 20,678

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From: NorCal

Round case mufflers are easier to fit than oval case mufflers unless the oval is oriented vertically. Remember that the driveline is offset about two inches to one side so spacing between a horizontal oval case muffler get close to the frame rail and the driveshaft.

I've got those Magnaflows installed on my 2WD '70 (360FE/TKO-500). Very well made... They area as loud as Flowmaster 40s. Cab insulation/sound deadener is recommended. But "noise" is highly subjective so it's your call.

Feb 17, 2016 | 02:30 PM

akguy09

Senior User

Joined: Nov 2014

Posts: 208

Likes: 1

From: North Pole,Alaska

On my Highboy the rear driveline isn't offset, its in the middle of the axle like 99% of vehicles. But round seem to fit the best

Feb 17, 2016 | 02:37 PM

Steven@nd

Elder User

Joined: Jan 2003

Posts: 759

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From: North Dakota

Glass packs would be my choice!

Feb 17, 2016 | 04:20 PM

77&79F250

Moderator & parts slinger

Joined: Feb 2007

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From: S/W Missouri, Polk county

Ovals will work, if you have a good exhaust guy.

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Feb 17, 2016 | 07:09 PM

HIO Silver

Fleet Owner

Joined: Dec 2009

Posts: 20,678

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From: NorCal

True. Ovals will work if ya stand them sideways.

Feb 17, 2016 | 09:06 PM

PA74F250

Cargo Master

Joined: Jul 2010

Posts: 2,099

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From: York, Pa

I have the oval Magnaflows on my highboy in 2.5". I really like the way it sounds except for when I really get on it. It's just too much crack in it out of my 445. I'm almost decided on adding a resonator ahead of them. Here's a idle video: