14 Sierra 5.3 Header questions

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Jun 9, 2018 | 01:29 PM

SierraBoy325

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14 Sierra 5.3 Header questions

Hi, new member here and I have a 14 Sierra 4x4 with a 5.3. I want to go with a set of long tube headers from speed engineering with off road y. Should I go with 1 3/4 or 1 7/8? Right now I just have bolts on, 6.2 intake/throttle body sway, K&N cold air, tune and exhaust. I might do a cam swap next year but don’t plan on boosting. This truck is my daily and I do tow a bass boat on occasion. For the guys who did it how hard of a job was it to fit them in? Any tips? Also will I need O2 extenders? Should I get better gaskets? Anything else needed for install? Any help is much appreciated Thanks!

Jun 9, 2018 | 09:25 PM

01FormulaTA

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From: H-town

stick with 1 3/4", you lose too much low end with 1 7/8" on a N/A 5.3....install is very easy and straightforward...you should be able to fit them both in from the top, disconnect the steering shaft to make it easier...reuse your stock exhaust manifold gaskets, if you want new ones go to the dealer, never ever use after market exhaust manifold gaskets, they are all trash and will leak, no O2 extensions will be required but you will need a tune or your CEL will come on...

Jun 9, 2018 | 09:47 PM

ZO6Ted

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Joined: Jan 2007

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From: Arlington, TX

I probably have to second that on 1 3/4 since its going to not ever be boosted. I recall the 1 7/8 lose less low end than we would normally believe though based on ls engine tests I've seen in the past. But, I do think they are probably overkill on a 325 even cammed especially on a heavy truck. Imo.