6.5 Diesel Exhaust on 454

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300stw

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jus t got the 4in diesel exhaust done,, what a pain in the ,,, getting the 3in to 4in y connected to the 4in system, the Y and the 4in pipe are the same size, where you cut the piping on the 4in system, so you need the 4in y bumped up at an exhaust shop to slide over 4in piping, will make your life easier, no one has mentioned that, all the brackets ect went on great, i used a donaldson 4in bus muffler that is 4ft long, nice tone at idle, really quiet in cab at freeway speeds, can hear exhaust when you run it hard, truck accelerates much better, less throttle to maintain 75 mph, cant wait to tow with it, i had dual 3in with cats and dual 3in mandrel bends after cats with flowmaster 40's was loud, in cab, ect,,, i didnt install cats as of now, exhaust smells fine,

i really like this whole system,, factory exhaust manifolds also, soon will be a 0411 swap and a tune
 

TexasT

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Can I get a source and/or part numbers for the collector pipes here? I looked at the gibson site but just found headers and tailpipes and mufflers. I see the cp106da and the other ones there but cant make em out and cant get anything with a google search, just guitar stuff.

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thanks for your help.
 

ZRoe

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What we be the consensus on the single 4" pipe vs keeping the factory 3" stainless pipes and using 2 x 3" SS mufflers?

A 4" pipe is 12.5sqin
2x 3" pipes are 14sqin

My thoughts are that my factory pipes are still okay and from a cost perspective the collector pipe from flowmaster is $115 and isn't even SS, plus $250 for the diamond eye kit which is aluminized.

I can get 2x 3" SS Borla Pro XS for $100ea and then do a turn down before the axle for an all in cost of $300.

The downfall with the dual 3" mufflers might be lack of scavenging and difficult to route two pipes out the back for Suburban owners like me.

Anyone else want to chip in?

Sent from my moto e5 supra using Tapatalk
 

ZRoe

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Can I get a source and/or part numbers for the collector pipes here? I looked at the gibson site but just found headers and tailpipes and mufflers. I see the cp106da and the other ones there but cant make em out and cant get anything with a google search, just guitar stuff.

You must be registered for see images attach


thanks for your help.
They are from Diamond Eye performance not Gibson. Should be able to find them there. They only make aluminized for the gmt400s

Sent from my moto e5 supra using Tapatalk
 

Crazydavez28

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What we be the consensus on the single 4" pipe vs keeping the factory 3" stainless pipes and using 2 x 3" SS mufflers?

A 4" pipe is 12.5sqin
2x 3" pipes are 14sqin

My thoughts are that my factory pipes are still okay and from a cost perspective the collector pipe from flowmaster is $115 and isn't even SS, plus $250 for the diamond eye kit which is aluminized.

I can get 2x 3" SS Borla Pro XS for $100ea and then do a turn down before the axle for an all in cost of $300.

The downfall with the dual 3" mufflers might be lack of scavenging and difficult to route two pipes out the back for Suburban owners like me.

Anyone else want to chip in?

Sent from my moto e5 supra using Tapatalk

If my truck had a non hack job exhaust when I bought it I wouldn't have touched the exhaust. Starting from essentially zero the diamond eye kit and flowmaster Y was a pretty easy install. Plus I used the extra pieces when I re-did all this for my longtubes. I don't think a mildly built 454 will be choked down much in the towing ranges by a dual 3 into single 4" system. 3" Duals are not cheap or easy to route over the axle.

Also, at the time I was pretty sure the factory pipes were 2.75" or 70mm whichever GM used.
 

MIHELA

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They are from Diamond Eye performance not Gibson. Should be able to find them there. They only make aluminized for the gmt400s

Sent from my moto e5 supra using Tapatalk

I am also interested in a y pipe like that but I cant find it on Diamond Eye's website either. I think I could make that work well on my setup right now I'm choking my motor with a modified 350 y pipe.
 

Crazydavez28

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I am also interested in a y pipe like that but I cant find it on Diamond Eye's website either. I think I could make that work well on my setup right now I'm choking my motor with a modified 350 y pipe.

The setup Fez has in the pictures is a Gibson Shorty headers package (GP106S-C). It includes the new y pipe but it's not shown in any of the pictures on Summit. Looks a lot simpler than long tubes and custom Y-pipe. My long tubes required some work to weld in O2 bungs and EGR port.
 

Mangonesailor

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I purchased my Gibson Headers with that in mind but did not sacrifice my goal just for ease of install, I hope it all plays out well.

I'm not sure if you've installed these yet, but you will likely have to grind some little notches on the flanges above where the head bolts are to fit them on for the passenger side. I think there were two spots that needed some extra room. Just keep that in mind in case you're putting exhaust sealant or something on your gaskets first.

I also kept mine in the bags and handled them as long as possible like that until they were bolted in place and I wouldn't be messing with them. Mine are ceramic coated and are just barely showing some surface rust. Keep them clean and they'll last. My set is 4-5yrs old now.

Gibson did a good job with the EGR fitting placement. No issues there. But their pipes to fit up to the factory stuff sucked. The O2 bung was also interfering with the floorpan with the sensor installed. I capped it and drove the truck with open headers to the exhaust shop to have everything else made to fit. Good call getting that other kit. I hope it helps.
 

MIHELA

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The setup Fez has in the pictures is a Gibson Shorty headers package (GP106S-C). It includes the new y pipe but it's not shown in any of the pictures on Summit. Looks a lot simpler than long tubes and custom Y-pipe. My long tubes required some work to weld in O2 bungs and EGR port.

Wouldn't work for me unless I get Caddy flanges and weld them to the headers. It can be done but I wouldn't want to butcher expensive headers when I can get them from CadCo. I wonder if they would sell the y-pipe separately.
 
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