Stock LT4 exhaust manifolds and throttle body

[Paul G]

Are the factory LT4 exhaust manifolds the same as the LT1 manifolds? The reason I am asking is because my LT4 has shorty headers on it, I might want to return it to bone stock someday. I will need an original set of exhaust manifolds to do that.

Same question about the throttle body. I have a BBK T.B. on it now. Same reason.

Thanks

[B17Crew]

Paul G,
I’m not sure about the header question, but the ’96 throttle body is unique to the ’96 Corvettes -- as is the LT4 exhaust system. The LT4 has a balance tube near the differential where the LT1 equipped Vettes do not.

I looked on Art’s Corvette Parts site to reference the manifolds,

http://www.artscorvetteparts.com/

Art’s list that the manifolds will fit ’92-’96. Definitely not the final say, I’d do more research and get hard facts.

I myself am in search of LT4 specific parts. I have been buying up LT4 parts for about the past year and a half as I intend to keep this car a long, long time (and in OEM condition). Someday when my schedule slows down, I want to enter it in judged events.

If you have a LT4 and want specific parts, BUY THEM NOW! Here’s a copy of an email I sent to Art’s Corvette Parts, Art’s reply is at the bottom:

Good Afternoon Mike,

I was refereed to you by Jackie at Davies Corvette.

I’m looking for a NOS or OEM 1996 LT4 driver side, black plastic fuel injection fuel rail cover. GM part number is 12552431. It would have “CORVETTE” painted in red lettering. If available, I’d be interested in the two plastic fasteners that secure the throttle cable to the top of the cover as well. A Corvette emblem logo is attached at the top-back of the part.

I would like a NOS part if available, but if you have the part off a low mile LT4, that may suffice, as long as the part is not heat faded (black plastic is going gray and the red lettering is showing signs of fading.) If off a low mile car, I’d appreciate the nicest one you’ve got as I want to put this on a LT4 that I will be entering in judged shows.

Can you tell me if you have this available and what the cost of the parts as
well as the shipping would be?

Davies Corvette Reply:
Unfortunately we have no covers left in stock. LT-4 parts are
becoming a real problem, respectfully, Mike

----- Original Message -----
To: <sales@artscorvetteparts.com>
Sent: Monday, January 17, 2005 4:06 PM
Subject: Attention Mike...

B17Crew

[Paul G]

That is what I am thinking. If I dont start finding the original parts now they will not be around for much longer. LT4 cars are very hard to find. I know of only two in the area. This summer I will have to look at them closely to see if I can spot any differences between there manifolds and LT1 car manifolds. Like you I am entering the Corvette in judged shows. Local shows right now but as time goes on I may want to enter in really fussy competition. For that it must be bone stock. With the headers, T.B., and Power effects exhaust this car goes like stink. But in a show like Bloomington Gold or Gold Spinner that stuff will cost points.

[B17Crew]

If your not getting offers on your car already, I think in the future you will, a ’96 CE LT4 Vert with the red interior is a very desirable car, a keeper for the long run.

Within the past couple of years, I’ve had two serious inquires about my LT4, and it’s only the Polo Green. I think those inquires were due to the low availability of the LT4 (and the condition my car is in).

It feels pretty good to say “sorry, but it isn’t for sale”... makes me feel like I truly have something.

B17Crew

[LT4BUD]

. I will need an original set of exhaust manifolds to do that.

I have just put long tube headers on my LT4......my stock manifolds would be for sale if you are interested....let me know...

also the factory cats.........they are in good shape......can't use them with the long tube headers...

[Chetzki]

This thread sparked my curiousity. My headers have extra bolt holes on the engine block on both front and rear of each manifold. Anyone else have this? I bought this car over 2 years ago and haven't noticed anything that was not stock. However, the exhaust system has always looked good as new and I've wondered if it is original. How could I tell?

Chetzki

[Paul G]

I picked up a set of manifolds already. Thanks anyway. I still need to find a 96 throttle body if anyone has one.


Paul

[3 Deuce]

Don't want to burst any bubbles, guys, but you do know that every manual trans '96 is an LT 4....................we're not dealing with LT 5s here....for the rail covers, you can clean them and respray them black or crackle black and hand paint the lettering....another site had them done in Polo Green and red.....

[B17Crew]

Don't want to burst any bubbles, guys, but you do know that every manual trans '96 is an LT 4....................we're not dealing with LT 5s here....for the rail covers, you can clean them and respray them black or crackle black and hand paint the lettering....another site had them done in Polo Green and red.....

3 Deuce,

Howdy, another Polo Green LT4, cool... What color interior do you have?

Very true, existing parts can be “refurbished”. I have found that OEM LT4 specific parts are becoming increasingly difficult to buy at the parts counter at Chevy dealerships, or they are not available at all.

I’m one of those Corvette owners that has a goal of keeping the car as close to stock as possible for future NCRS judged events, so a repro part will not work for me... unless it was absolutely necessary. I’m currently looking to purchase a LT1 or LT4 six-speed vert to be my “fun” car. My LT4 coupe is bound for the show fields some day, that’s why I’m so anal about finding exact parts.

The LT4 and LT5 are apple and orange comparisons, keep in mind that there are fewer LT4s than LT5s.

B17Crew

[3 Deuce]

According to "Corvette Specs" C 4...6939 ZR 1s and 6359 LT 4s...ZR are over a 5 year period and were not built by Chevrolet...for other stock LT 4 parts try Scoggins-Dickey Chevrolet in Houston....my interior is black...I have the stock seats so I swapped right side for left side and got an almost brand new seat for the trouble

[B17Crew]

According to "Corvette Specs" C 4...6939 ZR 1s and 6359 LT 4s...ZR are over a 5 year period and were not built by Chevrolet...for other stock LT 4 parts try Scoggins-Dickey Chevrolet in Houston....my interior is black...I have the stock seats so I swapped right side for left side and got an almost brand new seat for the trouble

Only 20 more LT5s than LT4s, not much of a spread, eh?

Thanks for the tip of Scoggins. I had several dealers do a national search for parts with no dice on certain items; it’s great that they are networked together.

I’ve only seen one Polo Green with a black interior, it was an LT4 a coupe like yours.

B17Crew

[Paul G]

Keep an eye on ebay for GM parts. I found a brand new Grand Sport T.B. cover plate to put over my BBK T.B. Got it from a Chevy dealer in Chicago on Ebay. I was trying to hide the fact that the T.B. is not stock by putting a stock plate on it. You have to look really close to tell now. I still want a stock LT4 T.B. if I can ever find one.

[B17Crew]

Hey Paul,

Good find. Those parts are out there, just takes leg work, that’s part of the fun.

B17Crew

[toby]

[QUOTE=B17Crew]Only 20 more LT5s than LT4s, not much of a spread, eh?

That appears to be a difference of 620 more LT5 than LT4, if the numbers above are correct. It's not a completely fair comparison given that the LT4 was only produced in one year. Besides, LT4 convertibles are pretty common compared to LT5 convertibles.

Toby

[toby]

Duh ... make that 580.



[QUOTE=toby]

Only 20 more LT5s than LT4s, not much of a spread, eh?

That appears to be a difference of 620 more LT5 than LT4, if the numbers above are correct. It's not a completely fair comparison given that the LT4 was only produced in one year. Besides, LT4 convertibles are pretty common compared to LT5 convertibles.

Toby