Exhaust for 1998 L29

[EKOBS]

Does anyone have suggestions for an exhaust on a 1998 L29 1 ton crew cab? I plan on using the JBA long tube headers and being emissions legal, I can tig weld so oxygen sensors and egr bungs are no problem; but I‘m thinking the collector on my headers is less than desirable. I’d like to go to Burns Stainless for a pair of collectors, at the moment I lack the info. to fill out their engine spec. form, especially the stock head flow numbers. It is my understanding that our engines are generally primary length insensitive, but secondary length and o.d. sensitive. I would like to get this part correct if I can. This is a work truck, towing etc., so I’m working with a stock engine/computer, but open to stuff like cam./valvetrain and computer mods if they enhance it’s ability to do it’s job. Thank you guys for such a great forum.

 

[GoToGuy]

I have an LO5, but 5.7 easier. So 454?

 

[b454rat]

Not sure what your looking for?

 

[Erik the Awful]

This is a work truck, towing etc.

Don't overthink it. Buy some long tubes and weld up a dual 3" exhaust with an H or X pipe. Get the free-est flowing mufflers that meet your personal and legal decibel limit.

 

[BNielsen]

Here's the 454 thread; have a look around and see what you think.
Vortec 454 Thread
Personally, I'm putting JBA shorties on my truck (got them for practically free!) for ease of installation. You might have to fight with the long tubes a little in order to get them to fit, especially since your truck is a 4x4

 

[EKOBS]

I have an LO5, but 5.7 easier. So 454?

Hi, thanks for your reply, yes, it is the MPFI 7.4 (Gen.6 454).

 

[EKOBS]

Not sure what your looking for?

Thank you for responding. I’m open to all ideas, but I was specifically searching for stock head flow numbers. This would give the guys at Burns the info., along with cam. specs and other stuff I have, they need to recommend and supply a merge collector I could attach to my headers. I can tig weld and fabricate, but I do admire their work enough that I am willing to pay for it. From what I’ve found it seems that a properly tuned exhaust could be worth fifty to sixty lbs. of torque. I’m also interested in what other folks have done, it is helpful to have all sorts of ideas in my head before starting a project such as this.

 

[b454rat]

Cant think where it is, but there is a thread on Vortec 454s, think in this section...

 

[Frank Enstein]

The Burns Merge collectors are impressive but on a stock engine they might not make much difference, But every little bit helps!

If there is a Tri-Y header I always recommend that. Any engine under 8000 RPM will see gains with that type over a 4 into 1 header.

180 degree headers are even better but good luck getting them to fit!

I recommend a proper Y or at least an X pipe. The gains can be dramatic.

For this I would do dual 2.5" into a single 3" Y pipe

https://www.summitracing.com/parts/flo-y250300s

with a WLK-17769 muffler

https://www.summitracing.com/parts/wlk-17769

and the biggest glass-pack after as a resonator.

This tail pipe kit

Flowmaster 15902 Flowmaster Tailpipe Kits | Summit Racing

Free Shipping - Flowmaster Tailpipe Kits with qualifying orders of $109. Shop Exhaust Pipes, Tailpipes at Summit Racing.

www.summitracing.com

That would be optimum for 300 to 400 hp.

 

[EKOBS]

Don't overthink it. Buy some long tubes and weld up a dual 3" exhaust with an H or X pipe. Get the free-est flowing mufflers that meet your personal and legal decibel limit.

First, thank you for your response, and yes this is my most typical approach to things, i.e. starting with the JBA long tubes. I didn’t really care about specifics, just that they were long tubes (28”-40”) and that I didn’t have to do the bending and cutting. I‘m hoping to push the next part, merge collectors, off on someone else too; I could probably be even lazier and just leave the JBA sort-of collectors on there, but this is where I expect more involvement on my part will be necessary. I’ll want to come up with some sort of end-of-header support so that I don’t need to revisit this in the near future and O2 bungs between the collectors and the cats. This may also be an attempt to offset welding under the truck for doing it on the table through hopefully better planning. Anyways, once this amount of work is involved I start strategizing over ways to make it longer lived and/or more simple to fab./maintain. Sorry to be so long winded, it just seems to me that this is the point (merge collectors) that can make or break the success of this project.