Big block headers

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99burbK2500

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So, I've got a 99 k2500 suburban that I swapped a hot 5.3 in, well I sold the 5.3 and decided I want to go big block. So I'm hunting a L29 454 with harness and ecm to make it plug and play that I'll 411 convert so I can tune it better. Blah blah, so I'm trying to find long tube headers that have decent sized primaries and everything they make is 1 3/4. That I can find anyways. I even looked at 8.1 stuff and there isn't ****. So if I can find a set of 1 7/8 or 2in headers is what I'd like. I plan on doing a good amount of work to the big block and want it to breath.

Has anyone had any luck with a big block header from another application? Like a older truck or ?? Trying to find a off the shelf solution. Sold the 5.3 for $2,800 and I'm trying to get this thing done close to $3,000. Thanks in advance guys.
 

88monteSS

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Gmt400 454 tbi headers fit right in, but you have to fab something up for the egr if you're not going to eliminate it.

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99burbK2500

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From what I'm reading ls and bbc exhaust poets are really close and modifying headers to work on one or the other is common in the car world. I'ma go to the parts store tomorrow and compare exhaust gaskets and see. Maybe I can talk this guy out of wanting my long tubes with the engine. If not, LC2NLS6 if you want to sell those let me know and we can figure it out!
 

LC2NLS6

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So they are for sale?

Not for sale, I just wanted to share the parts # for what they used to say fit big block in the 4x4s, except if have optional rear suburban a/c lines in the way. I have been thinking of rerouting my a/c lines on the other side of the frame then back through, or cut two pipes and weld them up as a triY of sorts to clear those ac lines.
 

618 Syndicate

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From what I'm reading ls and bbc exhaust poets are really close and modifying headers to work on one or the other is common in the car world. I'ma go to the parts store tomorrow and compare exhaust gaskets and see. Maybe I can talk this guy out of wanting my long tubes with the engine. If not, LC2NLS6 if you want to sell those let me know and we can figure it out!
Have you figured out what needs to happen to make ls headers work?
 

Schurkey

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Perhaps a moderator will move this thread to the "Exhaust" sub-forum.
https://www.gmt400.com/forums/exhaust.32/


I'm hunting a L29 454... ...so I'm trying to find long tube headers that have decent sized primaries and everything they make is 1 3/4. That I can find anyways. I even looked at 8.1 stuff and there isn't ****. So if I can find a set of 1 7/8 or 2in headers is what I'd like.
Big-tube headers are almost certainly a mistake. You'll be unable to rev high enough to need that capacity; the L29 heads are dogs above 5K rpm.

The smaller tubes are better for this application. Higher velocity, better scavenging, more performance, less cost, easier fitment. There's essentially no downside.
 
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