first ls1 header done
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From: Orland Park, IL
Car: 1984 Z28
Engine: SLOW carbed ls
Transmission: TH400 with brake, 8" PTC converter
Axle/Gears: moser 9" 4.11
first ls1 header done
finished the drivers side header finally today, may have to cut down the headmann hustler collector just slightly though, haven't checked yet. Ground clearance is even with the oil pan bottom.

passenger side should be completed in a few days longer, waiting on more u-bends from summit.
more pics at the end of the post of updates.

passenger side should be completed in a few days longer, waiting on more u-bends from summit.
more pics at the end of the post of updates.
Last edited by xpndbl3; Feb 20, 2009 at 08:10 PM.
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From: Lexington, KY
Engine: 6.0L LSX Carbed
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Re: first ls1 header done
Driver side was the easy one for me that's why I started on that side. I figured between steering, booster, and brake lines in the way it would be the hard one. I was wrong the pass side gave me all kinds of trouble. Just stay with it and remember it will all be worth it in the end.
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Re: first ls1 header done
Originally Posted by 6.LIROC-Z
Just stay with it and remember it will all be worth it in the end.
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From: Orland Park, IL
Car: 1984 Z28
Engine: SLOW carbed ls
Transmission: TH400 with brake, 8" PTC converter
Axle/Gears: moser 9" 4.11
Re: first ls1 header done
Driver side was the easy one for me that's why I started on that side. I figured between steering, booster, and brake lines in the way it would be the hard one. I was wrong the pass side gave me all kinds of trouble. Just stay with it and remember it will all be worth it in the end.
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From: Orland Park, IL
Car: 1984 Z28
Engine: SLOW carbed ls
Transmission: TH400 with brake, 8" PTC converter
Axle/Gears: moser 9" 4.11
Re: first ls1 header done

where it sits as of last night. Still haven't touched the passenger header, but did run the MSD 6010 box harness and redid half of it because the lengths are all wrong for a carb intake setup.
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Thread Starter
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From: Orland Park, IL
Car: 1984 Z28
Engine: SLOW carbed ls
Transmission: TH400 with brake, 8" PTC converter
Axle/Gears: moser 9" 4.11
Re: first ls1 header done
I have about 30 hours into these two headers now, so it isn't very cost effective including the $200 or so in flanges, u-bends and the collectors that I'm up to now. If a company comes out with 1 7/8" headers shortly then I will sell these off, otherwise I'm going to hold onto them.
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From: Guelph, Ontario
Car: 89 IROC/05 RX8
Engine: LS1/LS1
Transmission: T56/T56
Axle/Gears: 3.42 GM/3.55 8.8
Re: first ls1 header done
I have about 30 hours into these two headers now, so it isn't very cost effective including the $200 or so in flanges, u-bends and the collectors that I'm up to now. If a company comes out with 1 7/8" headers shortly then I will sell these off, otherwise I'm going to hold onto them.
How many bends do you have in these? Ive calculater 8 J bends, and 3 Straigh pipes + collectors and flanges.
Sheldon
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From: Orland Park, IL
Car: 1984 Z28
Engine: SLOW carbed ls
Transmission: TH400 with brake, 8" PTC converter
Axle/Gears: moser 9" 4.11
Re: first ls1 header done
What are the straight sections for? Each hooker u-bend had a 9" or so section of straight pipe on one end and 6" of pipe on the other end. I think I used 11 u-bends total with me probably having 1 left over when I'm done. I have 6 out of 8 of the tubes done, hopefully tomorrow I'll finish up the passenger side completely unless something pops up at the shop and I get pulled away from it. If I made 1 7/8" headers I'd probably step them to 2" then into 3.5" collectors if I was going to make my own set, but that's probably too extreme for the motor you're planning on running.
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From: Guelph, Ontario
Car: 89 IROC/05 RX8
Engine: LS1/LS1
Transmission: T56/T56
Axle/Gears: 3.42 GM/3.55 8.8
Re: first ls1 header done
What are the straight sections for? Each hooker u-bend had a 9" or so section of straight pipe on one end and 6" of pipe on the other end. I think I used 11 u-bends total with me probably having 1 left over when I'm done. I have 6 out of 8 of the tubes done, hopefully tomorrow I'll finish up the passenger side completely unless something pops up at the shop and I get pulled away from it. If I made 1 7/8" headers I'd probably step them to 2" then into 3.5" collectors if I was going to make my own set, but that's probably too extreme for the motor you're planning on running.
If i ordered 11 U bends in 1 7/8", then a 3" collector, that'd probably work for me.
I was figureing a 2.5" Y, to a 3" catback, but would the 2.5" Y be too small?
Build is a 346, MS3 cam, TSP CNC LS6 heads etc
Sheldon
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From: Calgary, AB, CA
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Re: first ls1 header done
Sheldon - have you thought of running the 3 inch collectors into a 3.5" single cat back. (2 x 3" in 1 x 3.5" Y) flow master makes a pretty decent Y for this at a good price (http://store.summitracing.com/partde...5&autoview=sku). There are better but they cost a ton more and are only a bit better. No need to choke the new motor
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From: Orland Park, IL
Car: 1984 Z28
Engine: SLOW carbed ls
Transmission: TH400 with brake, 8" PTC converter
Axle/Gears: moser 9" 4.11
Re: first ls1 header done
I'd do a dual 3" y-pipe with one of those flowmaster "y" connectors into a 3.5" catback and put a cutout there first, you'll pick up some power with the cutout no doubt. The 2.5" y-pipe would be a restriction as would the 3" catback, but the cutout will help when you are at the track, etc if you want to keep the 3" catback instead.
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From: Guelph, Ontario
Car: 89 IROC/05 RX8
Engine: LS1/LS1
Transmission: T56/T56
Axle/Gears: 3.42 GM/3.55 8.8
Re: first ls1 header done
I'd do a dual 3" y-pipe with one of those flowmaster "y" connectors into a 3.5" catback and put a cutout there first, you'll pick up some power with the cutout no doubt. The 2.5" y-pipe would be a restriction as would the 3" catback, but the cutout will help when you are at the track, etc if you want to keep the 3" catback instead.
If i ran a cutout, i could put a more restrictive muffler on, cause i want to keep a bit of a lid on the sound this year.
Magnaflow is very loud, and while the sound is to die for, my neighbours dont feel the same way when i wake up at 6am for work

I could do a 3" Y, then run a 3.5" single to a muffler of some sort, then just tuck the outlet, since im not a fan of the single tip look.
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From: Guelph, Ontario
Car: 89 IROC/05 RX8
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Transmission: T56/T56
Axle/Gears: 3.42 GM/3.55 8.8
Re: first ls1 header done
Was just juggling the idea.
If i ran the collectors into a 2.5" piping, X'd it and ran 2.5" true duals. Would that choke a 364 still?
If i ran the collectors into a 2.5" piping, X'd it and ran 2.5" true duals. Would that choke a 364 still?
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
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There are "stock appearing" 455 GS's and 454 Chevelles running low 11's and high 10's through manifolds and 2.5" duals. My 3900 lb '57 ran 11.9's through 2.5" dual tail pipes (not even mandrel bent).
I don't think you'll have a problem.
I don't think you'll have a problem.
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From: Orland Park, IL
Car: 1984 Z28
Engine: SLOW carbed ls
Transmission: TH400 with brake, 8" PTC converter
Axle/Gears: moser 9" 4.11
Re: first ls1 header done
I think the 2.5" duals will be fine, as for the stock appearing ones running those times, that's great but unchoke the motors and I bet they'd pick up a few more ponies on any chassis dyno.
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Re: first ls1 header done
If the difference between the 2.5 and 3" is like 5hp, i wouldnt bother. But if its 15+ id do the different
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From: Orland Park, IL
Car: 1984 Z28
Engine: SLOW carbed ls
Transmission: TH400 with brake, 8" PTC converter
Axle/Gears: moser 9" 4.11
Re: first ls1 header done
for a true dual setup or for a catback y-pipe? If you want to just run the cutout then I told you what to run, otherwise a nice 2.5" or 3" true duals would work. Both have to be bought new so might as well go bigger while you have that option. I'm putting 2.5" true duals with 3" cutouts immediately after the headers so for street duty it'll be quieter with the fullsize mufflers where the back seat bottom should have been in the floor.
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Re: first ls1 header done
kickass! very cool steve, glad to see some progress pics from you finally!
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From: Orland Park, IL
Car: 1984 Z28
Engine: SLOW carbed ls
Transmission: TH400 with brake, 8" PTC converter
Axle/Gears: moser 9" 4.11
Re: first ls1 header done
finished up the passenger side header today finally.
here's a shot of the drivers side installed


here's the passenger side on the welding bench
here's a shot of the drivers side installed


here's the passenger side on the welding bench
Last edited by xpndbl3; Feb 19, 2009 at 09:02 PM.
Thread Starter
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From: Orland Park, IL
Car: 1984 Z28
Engine: SLOW carbed ls
Transmission: TH400 with brake, 8" PTC converter
Axle/Gears: moser 9" 4.11
Re: first ls1 header done
finally finished both sides today and painted them in VHT header paint.
drivers side installed from behind

both headers installed....only .5" lower than the oil pan, should be perfect for ground clearance.

both headers from behind

passenger side header, now this is what I call tucked perfectly. .25" clearance all around the collector flange.
drivers side installed from behind

both headers installed....only .5" lower than the oil pan, should be perfect for ground clearance.

both headers from behind

passenger side header, now this is what I call tucked perfectly. .25" clearance all around the collector flange.
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From: Orland Park, IL
Car: 1984 Z28
Engine: SLOW carbed ls
Transmission: TH400 with brake, 8" PTC converter
Axle/Gears: moser 9" 4.11
Re: first ls1 header done
ya that's my buddies shop, i've kinda taken over his center lift for about the past 3 months. I think I've been in there 3-5 months out of every year actually now that I think about it. Not a bad gig for dealing with customers and answering phones, etc while he's out of the office. He has a 7 bay shop with 6 lifts.
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Re: first ls1 header done
I read this a couple of times and still am not sure what size primaries you used. and do you have any pics from the top side installed Thanks.
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Re: first ls1 header done
What are the straight sections for? Each hooker u-bend had a 9" or so section of straight pipe on one end and 6" of pipe on the other end. I think I used 11 u-bends total with me probably having 1 left over when I'm done. I have 6 out of 8 of the tubes done, hopefully tomorrow I'll finish up the passenger side completely unless something pops up at the shop and I get pulled away from it. If I made 1 7/8" headers I'd probably step them to 2" then into 3.5" collectors if I was going to make my own set, but that's probably too extreme for the motor you're planning on running.
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