LSx headers for 2nd gen?

[Zedzag]

I'm going to dump a 6.0 LQ9 gen III motor in my 81Z. Anyone know of a company who makes a ls1 header for a 2nd gen swap?

[Ralph LoGrasso]

I'd say your best bet would be street and performance. They'll probably have a shorty header that will work. I don't know of anyone that makes a Long Tube header for a 2nd gen LSx swap, or 1st gen for that matter (without a rack and pinion conversion). I think their website is www.streetandperformance.com

[Zedzag]

I may have to use the factory exhaust manifolds. I hear they're pretty good...probably close to as good as a shorty header. For a long tube I think I'll have to go custom and big$$.

[dennis68]

The factory C5 manifolds on the crate engine are only giving up 9HP at peak vs several different FL header manufacters. I am looking at doing a genIII swap too, I'll be running manifolds.

[Ralph LoGrasso]

I hear the 02+ Z06 manifolds flow the best out of the manifolds. I didn't know they're only giving up 9hp to LTs though? Is that on stock cubes? Boosted application? Do you know what manufacturers? This is pretty interesting, I was unaware the gain was so small.

[dennis68]

New Car Craft Ralph, yes it is on the stock Z06 crate engine from GMPP, N/A. I am not sure of the different manufacters tested, maybe I'll pick it up tonight to see.

[Ralph LoGrasso]

Okay cool, thanks. I'll try and pick that one up as well.

[Zedzag]

I bet a guy could pick up a set of those z06 manifolds off a guy who converted to headers for pretty cheap. Does the srticle say anything about the truck LQ4/LQ9 manifolds? I hear they work almost as good as the vette ones, especially under 6000 rpm.

[dennis68]

Naw, no other manifolds tested. I saw a pair of LQ9 manifolds on one of the LS1 boards for like 40.00.

They (Car Craft) aquired one of GMPP's ready to run crate LS1's and are upgrading it and dynoing all the results so everything is LS1 specific, not that it doesn't apply to virtually any genIII.

[LS1-S10]

I don't think C5 manifolds will work on a 2nd gen because they dump in the center almost like a street rod shorty. Alot of people resort to using the manifolds for stock applications, but by all means its a crutch to get you by. I've read on alot of forums that C5's are even picking up 15 rwhp with tuned length long tubes, and f-bodies are gaining over 20 to the rear wheels. Gen III motors are choked to death when there stock, much less modified. Any LS1 guru will tell you that headers should come before any internal engine mods, especially a cam swap which is where LS1's show the largest benefit.

If you feel up to fabrication and spending some time, i suggest you check out http://headersbyed.com/ . You can get a complete weld up kit with many options as far as primary and collector sizes, and flange size and thickness. I went this route on my S10 project because i want a perfect equal length 40" primary long tube, and no one makes a header for my hybrid project. My kit was about $540 and i got 2 extra 2" radius j-bends, 3/8 flanges, 1 3/4 primaries and 3" collectors with street hookup's. Ed has a wealth of knowledge when it comes to exhaust systems and headers, and his product is top quality and provides you with ALOT of interesting header info that you never knew about. He also told me that if i can build the header with near perfect primary lengths, and follow his specs that he wouldn't be suprised a bit if i gained 35-40 ft. lbs to the rear wheels with just the headers on a stock LS1.

If building a "perfect" header isn't really a big concern and you can live with most of your mass production name brand headers. I would simply buy a small block set of headers with your primary size and collector size, and modify the primaries to use a Gen III flange. Many people do this and you can come up with a nice fitting header that really isn't expensive. Versus over $1K to take your vehicle to a fabricator to make you a custom 1 off set. I really would leave the manifolds out of the scenario unless there your only option financially. I would also just stick with the manifolds over shorty type headers, the gains you see with them are so marginal, to me they don't prove themselves worth what they cost. I do believe i have heard that someone was using stainless work's LS1 long tubes for a 1st gen on a 2nd gen with no problems. I never was able to confirm this, but looking at them and looking at my 79 Z28, visually i believe they would work. However, don't take my word on it...just maybe an idea if you want to try that. I know if they did work alot of 2nd gen guys would be relieved.

[Zedzag]

I just read a post on LS1tech that someone used 4th gen pacesetter full length headers on a 79 LS1 swap with good results. Anyone else confirm this? Those headers are a good value.