need a recommendation on exhaust manifolds - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**yote1234** · 07-27-2025, 12:57 PM

I have a new sp357/350 crate engine in my 1971 k5 4x4 blazer and its exhaust manifold time. im a stock kind of person plus i have heard complaints of headers loosing up. the SP357/350 has vortec heads. so i believe rams horns are not an option. and the new stock cast iron manifolds dont seem to give room for plugs/wires.
with that being said can anyone give me some advice? i would appreciate very much.
Dave

**DeadheadNM** · 07-28-2025, 09:19 AM

Moved to pickup section for more eyeballs...

**A1971Blazer** · 07-28-2025, 09:48 AM

The bolt pattern will be the same on the vortec heads as the older SBC.
I bought a set of the Summit ram horns for my '70 Blazer that I removed headers from.
They fit well and have a 2½" opening for the exhaust pipe. Plenty of room for the plug wires.

Ironically I have the same SP350/357 crate engine that I'm going to put in that Blazer.
I plan on using the Summit manifolds. You can get them plain, black or shiny.

https://www.summitracing.com/parts/sum-g9200n
Name: sum-g9200n_xl.jpg
Views: 283
Size: 33.5 KB

Name: sum-g9200n_xl.jpg
Views: 283
Size: 33.5 KB

**Orefactory4x4 swb** · 07-28-2025, 12:31 PM

Quote:

Originally Posted by A1971Blazer

The bolt pattern will be the same on the vortec heads as the older SBC.
I bought a set of the Summit ram horns for my '70 Blazer that I removed headers from.
They fit well and have a 2½" opening for the exhaust pipe. Plenty of room for the plug wires.

Ironically I have the same SP350/357 crate engine that I'm going to put in that Blazer.
I plan on using the Summit manifolds. You can get them plain, black or shiny.

https://www.summitracing.com/parts/sum-g9200n
Attachment 2427596

I got a pair for my 72 and fit well.
The shinny ones

**yote1234** · 07-28-2025, 02:06 PM

Quote:

Originally Posted by DeadheadNM

Moved to pickup section for more eyeballs...

great idea i thank you,dave

Quote:

Originally Posted by A1971Blazer

The bolt pattern will be the same on the vortec heads as the older SBC.
I bought a set of the Summit ram horns for my '70 Blazer that I removed headers from.
They fit well and have a 2½" opening for the exhaust pipe. Plenty of room for the plug wires

Ironically I have the same SP350/357 crate engine that I'm going to put in that Blazer.
I plan on using the Summit manifolds. You can get them plain, black or shiny.

https://www.summitracing.com/parts/sum-g9200n
Attachment 2427596

AWESOME... I Thank you sooo much!!

Quote:

Originally Posted by Orefactory4x4 swb

I got a pair for my 72 and fit well.
The shinny ones

thank you!!!

**yote1234** · 07-28-2025, 02:19 PM

UPDATE: I just ordered a set for my SP357/350 and i appreciate all your help everyone

07-27-2025, 12:57 PM	#1
yote1234 Senior Member Join Date: Feb 2003 Location: Gold Canyon Arizona Posts: 4,546	need a recommendation on exhaust manifolds I have a new sp357/350 crate engine in my 1971 k5 4x4 blazer and its exhaust manifold time. im a stock kind of person plus i have heard complaints of headers loosing up. the SP357/350 has vortec heads. so i believe rams horns are not an option. and the new stock cast iron manifolds dont seem to give room for plugs/wires. with that being said can anyone give me some advice? i would appreciate very much. Dave __________________ 1971 K5 CST Blazer 1965 C10 Short bed all original 1949 gmc 100 1968 Honda mini-trail z50a #377 1966 uh 1-D Huey

07-28-2025, 09:19 AM	#2
DeadheadNM Carpe manana Join Date: Dec 2010 Location: Eau Claire, WI Posts: 12,579	Re: need a recommendation on exhaust manifolds Moved to pickup section for more eyeballs... __________________ 1972 K5 CST Highlander Blazer: http://67-72chevytrucks.com/vboard/s...d.php?t=708547 1972 K20 Cheyenne Super: http://67-72chevytrucks.com/vboard/s...d.php?t=528308 Members met: ORANGBLAZ, 2003 silverado, MikeCofield, BB72CHEVKT, Duncan&Son, Sameyrasmea72, THENEWMEXICAN, HotRod C/10, brianthelion02, Sport/Truck, ryanroo, michael bustamante, Dirt's72, Already Gone, WestButteTruck, 57taskforce, Moreyel, painterljp, AASmedic, SoCoC10, Lumaestas, carbuff382, Chevyland

07-28-2025, 09:48 AM	#3
A1971Blazer Senior Member Join Date: Nov 2013 Location: East Tennessee Posts: 2,408	Re: need a recommendation on exhaust manifolds The bolt pattern will be the same on the vortec heads as the older SBC. I bought a set of the Summit ram horns for my '70 Blazer that I removed headers from. They fit well and have a 2½" opening for the exhaust pipe. Plenty of room for the plug wires. Ironically I have the same SP350/357 crate engine that I'm going to put in that Blazer. I plan on using the Summit manifolds. You can get them plain, black or shiny. https://www.summitracing.com/parts/sum-g9200n __________________ 1967 C10 Step side 1968 C10 Step side 1970 Chevrolet K/5 Blazer ............. Last edited by A1971Blazer; 07-28-2025 at 09:58 AM.

07-28-2025, 02:19 PM	#6
yote1234 Senior Member Join Date: Feb 2003 Location: Gold Canyon Arizona Posts: 4,546	Re: need a recommendation on exhaust manifolds UPDATE: I just ordered a set for my SP357/350 and i appreciate all your help everyone __________________ 1971 K5 CST Blazer 1965 C10 Short bed all original 1949 gmc 100 1968 Honda mini-trail z50a #377 1966 uh 1-D Huey Last edited by yote1234; 07-28-2025 at 02:25 PM. Reason: answered my own question



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