Looks like you've got a good start, TJ. I've noticed the same about the manifolds. But, I've heard from the "experts" that these are still considered manifolds vs the LTx factory "shorties". Never figured that one out....

But, from another poster, I read the L98 ports are damned small. Something like 1.25" effective area. And, they have air tubes creating LOTs of turbulence. This is the biggest reason I chose to replace them. And, this Tri-Y design seemed most promising for street headers.

Personally, I'm not happy about no room for front CATS. But, I also realize their length is a strong-point of the design. I'm anxious to hear feedback. Got any idea when you'll be done?

That deal with the bolts stinks. I'm kinda disappointed that Brian didn't notify everyone from this batch of the potential problem!!!!!

Have you considered alternative bolts/gaskets?

How much are you going to insulate? I remember JetHot as having the property of insulating the pipes -- but I don't remember how much. If I don't bail (for shorties -- or shorter LT's), I'm kicking myself for not picking the double coating -- just for heat reduction.

gp

 

Just wait 'til you guys try to install the pass side. Less than 1/4"
between #2 tube and rear of upper control arm. For what
I'm trying to accomplish, I shoulda got shorties.
This is when you press on regardless...

 

Hi,

I just got the pass/side installed. I had no clearance to the upper control arm. I had to hit the tube with a hammer and dolly to clear. Still very tight. On the plus side-the header has plenty of ground clearance and was easy to install. I will post some photos.

Which gaskets are you (all) using?

Edit: Added comment. I am going to check the motor mounts. Maybe this is why the header is close. I will update.

Steven

 

To clear what (if not control arm)?

 

Header tube to clear the control arm. Sorry I thought I was clear. As I also added on prior post "I am going to check the motor mount" This may be why its close.

Steven

 

Oh... I thought you meant you had no clearance problem. Now I realize you meant you had less than the 1/4" that Bob reported!

 

Brian is sending a new set but I have decided to but a set from Summit that are drilled for tie wire. Chap and affective means to keep bolts from backing out.

I am purchasing a set of 1" verses the 3/4" supplied. The hefty 3/8" flange, a washer and the gasket leaves 3/8" in the head. That's twelve threads, and the thread depth is 3/4". Too little in the head for my tastes.

I should be done with the rough install Saturday and will post pictures.

TJM

 

What size tubes? 1-5/8" or 1-3/4" and once in is the fit reasonable.

In other words is this an install issue or a fittment issue?

Thanks

TJM

 

Hi,

It is definately my motor mounts! I jacked the motor up and it went up over a 1/4 of an inch. I time trial a few times a year at LimeRock and Pocono and I am guessing this put a beating on the mounts.

So to answer your questions the tube size is 1 3/4 and there is NO fitment issue at all (so far I only installed the right/side). I did not even remove the starter. Also no issues with ground clearance. Of course I should have check this first before putting a hammer to the headers

I will post some photos soon.

Steven

P.S. please excuse any misspelled words.

 

Photos added

 

Hi.

I have the same set of pictures and the same issues.

The driver’s side went in easy. The passenger went in easy if you loosen up the control arm [ count your shims!!!]

Pretty happy with that, at that point.

BUT! # 2 tube has zero clearance on the control arm nut and bushing sleeve.

I guess we both have bad motor mounts? Brian needs to fix this it is not right.

The drivers side collector extension 1 3/16’ from the floor pan. Customs Y pipe a must.

Pictures when I get my plug.

I would not recommend these to a novice wrench puller.

TJM

 

Alright, for all those Voyeurs out there , Pictures !

#1 Bob's issue. This collector extension will make an ashtray. A new extension is required to be fab'd. Do-able, but not if your Joe Shade Tree.



Pass side is great [ for the exhaust anyway]



Bottom view of both



Top down view on Pass side.



Look close at the bolt threads on AC bolt. That's JET HOT coating. Back the thing out if it protrudes.






More of the issue on the Drv. side collector.




Drv. side view [ I miss orange blocks].



Drv side top down Esay



See the upper control arm? It is all the way outand needs to be to install.



TROUBLE IS you have to run the arm back in. Zero clear.

I Radius'd the Arm Bushing Washer and Nut and am still not satisfied. The Pass side is going to come our and an indention made. Not the end of the world, BUT this is not a good commercial for Vette Tech.

My motor mounts is tired, but are you supposed to discover that problem, when the new ones wear , by boring a hole in your headers?

The design is flawed right here and needs some work. A different angel and a bit of tweeking and theses are Jam Up.

[To bad I'm doing the tweeking?].





* * *

I had a Drag Racing Motor Head helping out [ sort of Tom sawyer painting a fence thing].

He wants a set. He has put on more headers that I have socks, and except for the Control Arm issue, the install was pretty easy and fit was good.

[ with the exception of the *%&*<: @!!*% control arm thing]

He likes the look and sees the point of them.

This guy has four cars from a Malibu with a 400HP 383 to a 74 Nova with a 1,500 HP 502 BB. [ Oh ya, a 94 LT1 and that's where his set will go.]

His opinion I listen too.

TJM

 

Hi TJM,

You hit the nail on the head. On my car, with the negative camber I run for roadracing it puts the A-Arm even closer to the header. There is room to move that tube away. Other than this issue the fit is good. While my motor mount is bad-a new one will only net me an extra 1/4 inch +/-. Brian recommended adding an engine limiter on the drivers side.

Keep us posted on how you solve this problem. I will do the same.

Steven

 

I would have never thought this thread would last this long. Many thanks to all those who've added to it and taken the first bullet with the install of these headers, especially TJM. I wondered if the auto box folks would have some clearance issues however I never thought the control arms would be an issue.

Steve, I'm assuming you have an LT1/4 6 speed, since I have a 92 manual I'm interested in your install. What exhaust are you running and how do you plan to connect everything up? I have a Corsa exhaust with TPIS long tubes connected to dual Random Cats and custom pipes to the resonator right now. Where I currently live there are no smog checks so I'm riding the fence on leaving the cats off for now. If I do use them I'm looking at shortening the exhaust pipes on the resonator and moving it aft then mounting the cats directly in front of it in the tunnel. Either way I'll have to have a pair of pipes bent. Can you post a few more pics of your install to include a pic when it's all done?

Thanks again to everyone.....

jeff

 

What's an engine limiter? Some kind of shim?

Edit:

Or does this limit engine torsional rotation. Regardless of the clearance in your garage, what happens when you rev the motor and it torques sideways. (I don't remember which way it torques in the engine compartment, but there might be some rebound either way).

I was looking at how much length these headers have before they turn down. It seemed something had to hit.

 

Bob,
Tom (TJM) showed pics of his collector hitting the transmission pan. And, he said this was your issue with the collector. To be honest, I thought your issue was hitting the floorpan where the storage compartments come down. (In other words, making the bend over to the center w/o hitting that area).

I assumed you had a stick because of your Z51 model. Do you have an automatic? If so, does this say the collectors are more of an issue for those with automatic transmissions?


Tom,
How can you "dent" a primary tube (to aide in control arm clearance) w/o compromising the Jet-Hot coating?

Does removing the control arm bolt(s) require the car to be re-aligned after reassembly? (Hopefully not if you put the same number of shims back in).

How's the clearance on the control arm and steering linkage on the driver's side. I don't see a pic showing those potential contact points.

 

Jeff, yes I have a LT1 6spd. From the collectors-pipes to cats to X-pipe to Borla muffers (which is what came with the car when purchased).

Steven

 

Gregg, the engine wants to torque up on the drivers side and in-turn down on the pass/side. A limiter on the drivers side would help keep the engine from moving. What I am realizing, is that the tube on the pass/side (even with new motor mounts) is going to be close. On my car all the shims are removed (on the a-arm) to gain more negative camber. Therefore, bringing the a-arm closer to the tube. Hope to get this figured out!!

Steven

 

The collector issue is definitely a Drivers side floor pan issue, for sure. The one picture [ perhaps? ] of the Pass side is an optical illusion. There is sufficient clearance.

Regarding the Jet Hot coating, it will be compromised. I plan on making that flat spot with a shoe and press, rather than a hammer, then spray with a light grey High Temp paint. That's as good as it gets.

The drivers side is free and clear. #1 turns under as opposed to #2 that goes outside. No problems until you get to the collector.

Old Brian needs to do a little work here. That extension should be angled to accommodate the floor boards.

But this is an annoyance more than an issue. Brian will make improvements and the next guys will make out better. [ he gets the pictures and critiques, as well].

No realignment issues as long as the right number of shims go back in the same places!

 

Glad you're sending pics/feedback. I relayed my concern and Brian re-iterated his desire to change per your feedback. He said he would shorten #2 and the collector's.

I'm wondering if the bend (angle) is what's wrong on the driver's secondary tube(s). Should they be angled in toward the trans -- to avoid the floorpan issue?

Is there any way to shim up the motor/mounts? It wouldn't be my first thought/desire (wondering about drive-train alignment), but you don't know if you don't ask...

I'm trying to decide between return, waiting for re-design, or choosing another route.

Can't wait to hear feedback on performance!

gp