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1 5/8 or 1 3/4 headers

Old 06-29-2015, 09:26 AM
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Default 1 5/8 or 1 3/4 headers

Hey guys trying to make a planning decision for headers for my truck. Right now it's a bolt on 4.8 just an MIT tube and a 3" single. Wanna get headers next and I'm torn between going with Doug thorleys or the speed engendering headers.

Now the DT headers are tri y and 1 5/8 primaries which would be optimal for my 4.8 and everyone knows the specs for the Speed engineering headers.

My thought process is this. The 1 5/8 would be optimal for my 4.8 but leave very little room to grow. I'd like to do a 6.0 swap this time next year and I'm wondering if they would be a restriction on that a 6.0

Now if I get the speed engendering headers I will undoubtedly suffer some torque loss on the 4.8 which I need with heavy wheels and tires and a daily driver but maybe it wouldn't be so noticible because I am manual trans idk.

Torn between the two because the speed engeering are 200 bucks cheaper and give me a lot of room to grow but the DTs would be great for my 4.8 but are more expensive and I'm not sure if they would be a limiting factor down the road. Looking for some professional opinions from experience so let the bench racing begin! Thanks
Old 06-29-2015, 09:30 AM
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I honestly doubt you could feel the difference in the butt dyno.

Either header would work on either motor if you decided to swap, you'd have to be making some serious horsepower for them to be a actual restriction in flow.
Old 06-29-2015, 09:33 AM
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Default 1 5/8 or 1 3/4 headers

Originally Posted by FFDP
I honestly doubt you could feel the difference in the butt dyno.

Either header would work on either motor if you decided to swap, you'd have to be making some serious horsepower for them to be a actual restriction in flow.
Thanks that's all I use to measure power anyway not looking for big power dyno number or fast track times. Just want something that feels good on the street and sounds narly of course
Old 06-29-2015, 10:49 AM
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1 5/8 has no place on a LS motor
Old 06-29-2015, 08:55 PM
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Go with the cheaper ones.
Old 06-29-2015, 09:46 PM
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Default 1 5/8 or 1 3/4 headers

Originally Posted by George C....
1 5/8 has no place on a LS motor
Yeah even a stock mini mouse 4.8?
Old 06-29-2015, 09:47 PM
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Default 1 5/8 or 1 3/4 headers

Originally Posted by FFDP
Go with the cheaper ones.
I'd like to because then I'd have headers and a tune for the price of the thorleys but I don't wanna loose what little bottom end I do have
Old 06-29-2015, 10:09 PM
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Originally Posted by slick_sierra
Yeah even a stock mini mouse 4.8?
4.8 isnt so small as you think
Old 06-29-2015, 11:13 PM
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Default 1 5/8 or 1 3/4 headers

Originally Posted by George C....
4.8 isnt so small as you think
Yeah I know it's capable for sure. The speed engineering headers are a serious contender as I like there price and y pipe a bit better
Old 07-01-2015, 07:23 PM
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I'm making over 400rwhp on a 6m0 with 1 5/8 longtubes...
but I am changing soon

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