First time manifold question... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**'70_402** · 04-20-2005, 09:31 AM

I was getting all the surfaces cleaned up and ready for gasgets last night and i decided to put the manifold on there with no gaskets (just to check fit) and i noticed somthing that caught my eye.. (bear with me) where the exaust crossover is in the head there are ports around it.. and oil is in there.. well my manifold only covers the bottom part of those ports.. but the gasket covers them up all the way (i checked)... is this a problem.. i just thought it was wierd... here are a few pics of what i am talking about...

Alex Hayley · 04-20-2005, 01:05 PM

Set the gaskets AND mainfold on and see if there is a better match of the ports.

lngbed71 · 04-20-2005, 01:27 PM

Whew..don't know about that. Looks like too much exposed area for a gasket to take care of. Unless maybe the gasket set comes with the steel block-out like some small block kits do. Looks too goofy to me though......

Alex Hayley · 04-20-2005, 01:53 PM

Do you have extra thick head gaskets under the heads right now? Are the bolt holes from the manifold into the head off by the same amount as the ports? Are the heads and manifold original?

Mudder · 04-20-2005, 01:55 PM

That just doesnt look right........

Chris H · 04-20-2005, 02:13 PM

In looking at edelbrock's web pages, it looks like the Performer RPM Air-Gap is offered in 2 different part numbers:
7561 for 1975 and earlier oval ports or
7562 for rectangular ports

Could this be the problem? (wrong intake for heads?)

**'70_402** · 04-20-2005, 03:07 PM

I have the part number 7561, and the gaskets will cover it up when put on, but just like mudder said, it just doesn't look right.. i am curious what are those holes...

Here is the combo that i have.. this is basically stock motor..

Heads....#336781
Manifold... #7561
Gaskets...Fel-Pro #1210

arkracing · 04-20-2005, 04:31 PM

don't worry about it. mine looked like that too.

once i put the intake gasket on it covered the hole and i don't think that passage goes anywhere...the small hole in the middle does...but the surrounding one doesn't.

scared me too when i put my BBC together and i asked someone who's been a chevy guy for 40years said yeh that's how some of them are..and he was scared the first time he saw it too.

lngbed71 · 04-20-2005, 04:33 PM

Quote:

Originally Posted by Chris H

7561 for 1975 and earlier oval ports or
7562 for rectangular ports

Looks like you have a square port head configuration, and oval port manifold.

**'70_402** · 04-20-2005, 04:43 PM

Quote:

Originally Posted by lngbed71

Looks like you have a square port head configuration, and oval port manifold.

nope large oval ports.. #336781 large oval port manifold. #7561

Quote:

Originally Posted by arkracing

don't worry about it. mine looked like that too.

once i put the intake gasket on it covered the hole and i don't think that passage goes anywhere...the small hole in the middle does...but the surrounding one doesn't.

scared me too when i put my BBC together and i asked someone who's been a chevy guy for 40years said yeh that's how some of them are..and he was scared the first time he saw it too.

that is what i was thinking also... anyone else ever ran into this...

Alexis · 04-20-2005, 04:50 PM

have you called there tech line?

lngbed71 · 04-20-2005, 05:02 PM

Forgot about the large ovals.

cdyblu · 04-21-2005, 04:32 PM

it's normal, nothing to worry about.

mr402 · 04-21-2005, 11:46 PM

That's the way the big block heads are. The opening the arrow point to doesn't go anywhere or do anything except collect debris. Like you said, it was filled with oil. Likely just seepage from the valve cover over the years. Clean it out real well then use a sticky gasket adhesive in that area so the intake gasket will keep it sealed up. Has nothing to do with square vs. oval port.

We've all been through this once.

04-20-2005, 01:53 PM	#4
Alex Hayley Registered User Join Date: Jul 2000 Location: NC Posts: 987	Do you have extra thick head gaskets under the heads right now? Are the bolt holes from the manifold into the head off by the same amount as the ports? Are the heads and manifold original? Last edited by Alex Hayley; 04-20-2005 at 01:54 PM.

04-20-2005, 02:13 PM	#6
Chris H 72 C30 Trailer Queen Join Date: Dec 1999 Location: SE MN, USA Posts: 794	In looking at edelbrock's web pages, it looks like the Performer RPM Air-Gap is offered in 2 different part numbers: 7561 for 1975 and earlier oval ports or 7562 for rectangular ports Could this be the problem? (wrong intake for heads?) __________________ Chris H 72 C30 133" 72 C30 157" flat-dump 69 C10 short fleet 71 ElCamino 2000 K2500 crewcab shortbed (sold, sorry old friend) 2005 GMC 2500HD shortcrew Duramax 2006 K1500 RCSB and a couple other projects/parts

04-20-2005, 04:31 PM	#8
arkracing Weekend Warrior Join Date: Oct 2004 Location: CT Posts: 1,787	don't worry about it. mine looked like that too. once i put the intake gasket on it covered the hole and i don't think that passage goes anywhere...the small hole in the middle does...but the surrounding one doesn't. scared me too when i put my BBC together and i asked someone who's been a chevy guy for 40years said yeh that's how some of them are..and he was scared the first time he saw it too. __________________ -'07 GMC Sierra K2500HD -'66 C10 Suburban -'68/'71 K20 Service Bed Project -'69 Chevy C30 Mason Dump -'33Ford P/U 396ChevyPowered

04-21-2005, 04:32 PM	#13
cdyblu Registered User Join Date: Dec 2004 Location: Green Bay, WI Posts: 44	bb heads it's normal, nothing to worry about.

04-21-2005, 11:46 PM	#14
mr402 Registered User Join Date: Jan 2004 Location: Elmira, Oregon Posts: 449	That's the way the big block heads are. The opening the arrow point to doesn't go anywhere or do anything except collect debris. Like you said, it was filled with oil. Likely just seepage from the valve cover over the years. Clean it out real well then use a sticky gasket adhesive in that area so the intake gasket will keep it sealed up. Has nothing to do with square vs. oval port. We've all been through this once. Last edited by mr402; 04-21-2005 at 11:47 PM.

04-20-2005, 09:31 AM	#1
'70_402 Senior Member Join Date: Dec 2003 Location: Pampa, Texas Posts: 1,554	First time manifold question... I was getting all the surfaces cleaned up and ready for gasgets last night and i decided to put the manifold on there with no gaskets (just to check fit) and i noticed somthing that caught my eye.. (bear with me) where the exaust crossover is in the head there are ports around it.. and oil is in there.. well my manifold only covers the bottom part of those ports.. but the gasket covers them up all the way (i checked)... is this a problem.. i just thought it was wierd... here are a few pics of what i am talking about... Attached Images __________________ https://www.ebay.com/itm/29620574751...mis&media=COPY

04-20-2005, 01:05 PM	#2
Alex Hayley Registered User Join Date: Jul 2000 Location: NC Posts: 987	Set the gaskets AND mainfold on and see if there is a better match of the ports.

04-20-2005, 01:27 PM	#3
lngbed71 Nothing fits but the oil Join Date: Mar 2003 Location: Gaston, Indiana Posts: 424	Whew..don't know about that. Looks like too much exposed area for a gasket to take care of. Unless maybe the gasket set comes with the steel block-out like some small block kits do. Looks too goofy to me though...... __________________ Land of the free Because of the brave

04-20-2005, 01:55 PM	#5
Mudder Registered User Join Date: Feb 2001 Location: East Central, MO Posts: 11,336	That just doesnt look right........

04-20-2005, 03:07 PM	#7
'70_402 Senior Member Join Date: Dec 2003 Location: Pampa, Texas Posts: 1,554	I have the part number 7561, and the gaskets will cover it up when put on, but just like mudder said, it just doesn't look right.. i am curious what are those holes... Here is the combo that i have.. this is basically stock motor.. Heads....#336781 Manifold... #7561 Gaskets...Fel-Pro #1210 Attached Images __________________ https://www.ebay.com/itm/29620574751...mis&media=COPY Last edited by '70_402; 04-20-2005 at 03:29 PM.

04-20-2005, 04:50 PM	#11
Alexis Member since 2000 Join Date: Dec 2000 Location: Mountain View Ca / Mexico Posts: 7,879	have you called there tech line?

04-20-2005, 05:02 PM	#12
lngbed71 Nothing fits but the oil Join Date: Mar 2003 Location: Gaston, Indiana Posts: 424	Forgot about the large ovals. __________________ Land of the free Because of the brave



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