does anyone know if the exhaust manifolds are different for the dual cat system. i have a single cat system and i would like to upgrade to the dual cat system. like to know if the manifolds are different between each other or are they the same for both system.

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1989 iroc-z 350 TPI, auto trans, leather int. t-tops, edelbrock headers and cat back system, SLP cam, crane double roller chain, 4 wheel disc, and aftermarket hood. Iroc-z's forever, Ford Mustangs NEVER

 

I believe they are the same.

 

does anyone else have a second opinon?

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1989 iroc-z 350 TPI, auto trans, leather int. t-tops, edelbrock headers and cat back system, SLP cam, crane double roller chain, 4 wheel disc, and aftermarket hood. Iroc-z's forever, Ford Mustangs NEVER

 

same

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-Tas
'89 Formula WS-6

305, TBI, 700R4, P.A.W. 14x3 open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips, Hooker 1-5/8" 50 state legal headers, Dynomax 3" I pipe (PN 44063 and 43248)
Super GRK_Taz World
F-Body Dual Exaust
EFI & Intake Options

 

Yep, the 350's and 305 5-speeds use the same exhaust manifolds, regardless of single or dual cats. However the 305 automatics use the smaller TBI exhaust manifolds.

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1991 Camaro Z28
5.7L 5-Speed (originally 305)
317 RWHP, 418 RWTQ
13.23 @ 107.62 MPH (2.10 60')
Southern California
Member: SoCal 3rd Gen F-Bodies
Member: SoCal F-Bodies
-=ICON Motorsports=-

 

thanks guys for helping. wasnt forsure

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1989 iroc-z 350 TPI, auto trans, leather int. t-tops, edelbrock headers and cat back system, SLP cam, crane double roller chain, 4 wheel disc, and aftermarket hood. Iroc-z's forever, Ford Mustangs NEVER

 

Wait, I take it back. The 89-92 TPI cars with single cat use the smaller exhaust manifolds. The dual cats use the larger manifolds.

 

thanks. i am trying to find the manifold casting numbers for my car. if anyone knows, i will appreciate it alot. just want to get the right parts. thanks to all

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1989 iroc-z 350 TPI, auto trans, leather int. t-tops, edelbrock headers and cat back system, SLP cam, crane double roller chain, 4 wheel disc, and aftermarket hood. Iroc-z's forever, Ford Mustangs NEVER

 

I also want to put in a factory dual cat system. I thought all of the TPI exhaust manifolds were the same?

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90 IROC convertible, dead stock 305TPI and TH700R4
79 Malibu, 350, ZZ3 cam, Vortec heads, Performer RPM manifold Th200r4, GN rear, real sleeper(excuse for not doing any body work)

 

thanks for the reply. i am trying to find out if the manifolds are different. i should be getting some info related to the dual cats and i am hoping the it will include the casting numbers for all camaros. "LOOKING FOR EXHAUST MANIFOLD CASTING #'s FOR SIG BELOW, DUAL CATS"

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1989 iroc-z 350 TPI, auto trans, leather int. t-tops, edelbrock headers and cat back system, SLP cam, crane double roller chain, 4 wheel disc, and aftermarket hood. Iroc-z's forever, Ford Mustangs NEVER

 

I did a search for you and found it:
https://www.thirdgen.org/messgboard/...ML/002616.html

 

thanks kevin91z. your reply is greatly appreciated. now i have to find a set of these manifolds. does anybody have a set of these manifolds for sale? needs to be a set for the dual cat system. thanks to all

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1989 iroc-z 350 TPI, auto trans, leather int. t-tops, edelbrock headers and cat back system, SLP cam, crane double roller chain, 4 wheel disc, and aftermarket hood. Iroc-z's forever, Ford Mustangs NEVER

 

Ill have a set of unwanted manifolds off of my 92 Z28 L98 dual cat car in a few days time when I have the SLP 1 3/4s in place, first fair offer and they are yours just give me an E mail if youre interested.....

 

Same here. I have the complete exhaust, with dual cats, manifolds, and a Flowmaster muffler. E-mail me with a price if you would like any of it.



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Joshua Johnston
1991 Z-28
350, T-5, K&N, Ported Vortec heads, Edelbrock RPM, Holley 750 D.P., HEI, 11.07:1 CR, Comp Cams Roller-.510"/.520"-282*/288* dur., Shorty Headers, Dual 2.5 Exhaust, Dynomax Bullet Mufflers, T&R Motorsports custom air intake, Bald tires