Stock Exhaust Manifolds - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**RodnRudy** · 02-17-2019, 11:10 AM

Can any of you guys that have an engine with Vortec heads confirm that the stock cast exhaust manifolds will work on these heads? I'm thinking of buying a vortec 350 and don't want to run headers but use my existing exhaust.

bob arrington · 02-17-2019, 12:00 PM

If I remember right, they will bolt up but sit higher on the head than the vortec manifolds and are a bit wider. That was vortecs on an early block. you may need to use a manifold spreader. I think one of the holes was bout a 1/16" off. I'm sure someone may have more recent info. Hope this helps

**chiefcfd** · 02-17-2019, 01:09 PM

I have the Repros on mine. It is the 5.7L Vortec HO.

B. W. · 02-17-2019, 01:21 PM

They will bolt right on. Here are pics showing the vortec exhaust gasket on a stock L31 manifold & a rams horn:

**RodnRudy** · 02-17-2019, 02:29 PM

Quote:

Originally Posted by B. W.

They will bolt right on. Here are pics showing the vortec exhaust gasket on a stock L31 manifold & a rams horn:

From the pic I don't see any leakage problems with the gaskets. Did you use the L31 exhaust gaskets with the earlier manifolds or the earlier style gaskets?

B. W. · 02-17-2019, 05:03 PM

I used the L31 gaskets. The are MLS (Multiple Layer Steel) and work well. Victor Reinz MS16093T.

6T7 C10 · 02-17-2019, 08:42 PM

I have had good success with aftermarket ram horn exhaust manifold on vortec heads. Been on a year with about 500 miles.

Sorry about the upside down pics. I rotated them several ways and each time uploads upside down. I guess use your imagination.

**RodnRudy** · 02-17-2019, 09:26 PM

Thanks for the help on the manifolds fellas. Now I have to make up my mind if I want to pull the trigger on the engine.

**truckster** · 02-17-2019, 09:53 PM

Quote:

Originally Posted by RodnRudy

Thanks for the help on the manifolds fellas. Now I have to make up my mind if I want to pull the trigger on the engine.

Do it. You'll love it.

Mine current one is almost done. It has HEI and a Quadrajet. The only internal upgrades I made were stiffer springs and the HT 383 cam. It should be good for around 330 HP and 400 lb-ft torque.

**Steeveedee** · 02-17-2019, 10:24 PM

Quote:

Originally Posted by 6T7 C10

I have had good success with aftermarket ram horn exhaust manifold on vortec heads. Been on a year with about 500 miles.

Sorry about the upside down pics. I rotated them several ways and each time uploads upside down. I guess use your imagination.

Just going to be a Men in Black truck, driving upside-down.

**Boog** · 02-17-2019, 11:29 PM

Fixed

toolboxchev · 02-18-2019, 03:37 AM

Quote:

Originally Posted by chiefcfd

I have the Repros on mine. It is the 5.7L Vortec HO.

Where did you get the stock serpentine assembly with out the smog pump and AC compressor?

Or is that just an everyday item?

02-17-2019, 11:10 AM	#1
RodnRudy Senior Member Join Date: Oct 2014 Location: New Palestine In Posts: 930	Stock Exhaust Manifolds Can any of you guys that have an engine with Vortec heads confirm that the stock cast exhaust manifolds will work on these heads? I'm thinking of buying a vortec 350 and don't want to run headers but use my existing exhaust. __________________ Phil "Money is only a tool to create and achieve what you want most in life" PayPal: rodnrudy@comcast.net

02-17-2019, 12:00 PM	#2
bob arrington Registered User Join Date: Dec 2018 Location: Clitherall Posts: 56	Re: Stock Exhaust Manifolds If I remember right, they will bolt up but sit higher on the head than the vortec manifolds and are a bit wider. That was vortecs on an early block. you may need to use a manifold spreader. I think one of the holes was bout a 1/16" off. I'm sure someone may have more recent info. Hope this helps

02-17-2019, 01:09 PM	#3
chiefcfd Senior Member Join Date: Oct 2010 Location: Cadiz, Ky Posts: 510	Re: Stock Exhaust Manifolds I have the Repros on mine. It is the 5.7L Vortec HO. Attached Images __________________ 1972 Chevy LWB Roadster 1999 Chevy Silverado 2wd 2015 Chevy High Country 4x4 Crew Cab

02-17-2019, 01:21 PM	#4
B. W. Registered User Join Date: Nov 2014 Location: Bigfork, Montana Posts: 1,137	Re: Stock Exhaust Manifolds They will bolt right on. Here are pics showing the vortec exhaust gasket on a stock L31 manifold & a rams horn: Attached Images

02-17-2019, 05:03 PM	#6
B. W. Registered User Join Date: Nov 2014 Location: Bigfork, Montana Posts: 1,137	Re: Stock Exhaust Manifolds I used the L31 gaskets. The are MLS (Multiple Layer Steel) and work well. Victor Reinz MS16093T.

02-17-2019, 08:42 PM	#7
6T7 C10 Registered User Join Date: Feb 2015 Location: TX Hill Country Posts: 150	Re: Stock Exhaust Manifolds I have had good success with aftermarket ram horn exhaust manifold on vortec heads. Been on a year with about 500 miles. Sorry about the upside down pics. I rotated them several ways and each time uploads upside down. I guess use your imagination. Attached Images Last edited by 6T7 C10; 02-17-2019 at 08:44 PM. Reason: Upside down pics.

02-17-2019, 09:26 PM	#8
RodnRudy Senior Member Join Date: Oct 2014 Location: New Palestine In Posts: 930	Re: Stock Exhaust Manifolds Thanks for the help on the manifolds fellas. Now I have to make up my mind if I want to pull the trigger on the engine. __________________ Phil "Money is only a tool to create and achieve what you want most in life" PayPal: rodnrudy@comcast.net

02-17-2019, 11:29 PM	#11
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 12,949	Re: Stock Exhaust Manifolds Fixed Attached Images __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross



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