The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 01-10-2014, 03:31 AM   #1
79GMCSierra
Registered User
 
79GMCSierra's Avatar
 
Join Date: Dec 2013
Location: Folsom, CA
Posts: 17
79 GMC 4.1L 250 Cylinder Head Advise

Hi All,

After doing a through inspection of my new purchase I discovered the the cylinder head is cracked on the exhaust manifold that is part of the cylinder head.

I believe this head is known as an Integrated Head. Please correct me if I'm wrong.

Anyway I'd like to replace it with a Normal I6 head that has a separate Intake Manifold and Exhaust Header.

My little bit of research tells me that a 78 head might be what I'm looking for. Or as mentioned on another thread a 194 Head. More info on the 194 head would be greatly appreciated.

So what might be your recommendations, keeping in mind this is a California truck. Funny thing is... I just had it smog'd and it pasted with the cracked exhaust manifold.
79GMCSierra is offline   Reply With Quote
Old 01-10-2014, 07:25 AM   #2
79Betty
Registered User
 
79Betty's Avatar
 
Join Date: Jan 2013
Location: Jasper, IN
Posts: 948
Re: 79 GMC 4.1L 250 Cylinder Head Advise

If it passed smog i would just weld the crack up. Can't do much with a vehicle after 1974? In cali.
__________________
When in doubt, throttle it out!
1974 Chevrolet Custom K20
2005 Ford Ranger Edge
1985 Chevrolet Custom Deluxe C10
79Betty is offline   Reply With Quote
Old 01-10-2014, 11:31 AM   #3
D13
Registered User
 
D13's Avatar
 
Join Date: Feb 2007
Location: Memphis MI
Posts: 1,851
Re: 79 GMC 4.1L 250 Cylinder Head Advise

You can swap to a non-integrated, you will need intake/exhaust/carb and the carb linkage may not work. Is yours a 1 barrel or 2 bbl carb (take off air cleaner lid, if carb top is round, 1bbl, rectangular, 2bb)? There are no factory 2 bbl non-integrated mainfolds, so you would need aftermarket intake and carb or go to factory 1bbl.
194 head has smaller combustion chambers for a little more compression, but has siamesed exhaust ports so headers don't work as well. All the other non-integral heads are about the same. late 292 have AIR plugs in them so if you have AIR you would need those.
Rebuilt (or at lest cleaned and checked) integral heads show up on ebay time to time for $250-300. That's about what it costs to have a normal head reqworked, before you get the carb, intake, and exhaust. Just make sure you get the right one, and expect to add new rockers / gaskets, etc.
Oh, and buy Leo Santucci's book, version 2. Lots of good info on L6 even though it's heavy on race prep.
__________________
1987 2 ton
1982 250/TH350 beater in progress
Dad's 1981 3/4 L6 3 on tree posi and no options, awaiting restoration or scrapping
Plus a mess o' tractors
D13 is offline   Reply With Quote
Old 01-10-2014, 12:28 PM   #4
79GMCSierra
Registered User
 
79GMCSierra's Avatar
 
Join Date: Dec 2013
Location: Folsom, CA
Posts: 17
Re: 79 GMC 4.1L 250 Cylinder Head Advise

Quote:
Originally Posted by 79Betty View Post
If it passed smog i would just weld the crack up. Can't do much with a vehicle after 1974? In cali.
Yup that would work, or I may just replace it with a 79 remanufactured head. Thanks for your suggestion.

Quote:
Originally Posted by D13 View Post
You can swap to a non-integrated, you will need intake/exhaust/carb and the carb linkage may not work. Is yours a 1 barrel or 2 bbl carb (take off air cleaner lid, if carb top is round, 1bbl, rectangular, 2bb)? There are no factory 2 bbl non-integrated mainfolds, so you would need aftermarket intake and carb or go to factory 1bbl.
194 head has smaller combustion chambers for a little more compression, but has siamesed exhaust ports so headers don't work as well. All the other non-integral heads are about the same. late 292 have AIR plugs in them so if you have AIR you would need those.
Rebuilt (or at lest cleaned and checked) integral heads show up on ebay time to time for $250-300. That's about what it costs to have a normal head reqworked, before you get the carb, intake, and exhaust. Just make sure you get the right one, and expect to add new rockers / gaskets, etc.
Oh, and buy Leo Santucci's book, version 2. Lots of good info on L6 even though it's heavy on race prep.
It's a 2-bbl. Just ordered Leo's book. Thanks for all your input.
79GMCSierra is offline   Reply With Quote
Old 01-10-2014, 07:26 PM   #5
lilpoindexter
Registered User
 
lilpoindexter's Avatar
 
Join Date: Sep 2010
Location: los angeles
Posts: 1,134
Re: 79 GMC 4.1L 250 Cylinder Head Advise

My '78 California Truck has the crappy integrated head.
lilpoindexter is offline   Reply With Quote
Old 01-12-2014, 02:26 AM   #6
79GMCSierra
Registered User
 
79GMCSierra's Avatar
 
Join Date: Dec 2013
Location: Folsom, CA
Posts: 17
Re: 79 GMC 4.1L 250 Cylinder Head Advise

Talked with John from Autowerks today from Iowa and he said any I6 head can work from the 230 to the 292, but may need combustion chamber work. His machined & ported heads go for about $1,100... that's what I paid for the whole truck! Not sure if I'm ready for that. I'm going to keep a lookout for a non-inter-grated head. I'm thinking checking cylinder head gaskets to see what models they fit. Which may be a good clue where to look.
79GMCSierra is offline   Reply With Quote
Old 01-12-2014, 02:51 AM   #7
79GMCSierra
Registered User
 
79GMCSierra's Avatar
 
Join Date: Dec 2013
Location: Folsom, CA
Posts: 17
Re: 79 GMC 4.1L 250 Cylinder Head Advise

Quote:
Originally Posted by lilpoindexter View Post
My '78 California Truck has the crappy integrated head.
I feel your pain! Guess I should have done more research before I pulled the trigger on my new guest in the side yard. Oh well I'm learning...
79GMCSierra is offline   Reply With Quote
Old 01-12-2014, 09:54 PM   #8
beamn7
Registered User
 
Join Date: Oct 2011
Location: Wildomar, CA
Posts: 466
Re: 79 GMC 4.1L 250 Cylinder Head Advise

My 78 federal emissions C10 has the non-integrated head / 1bbl carb. Truck has been in the family since factory order and has 250K miles on her. Never been apart. Great engines! I would imagine you could swap it to a non-integrated and hope the smog guy is too young to even know what a L6 is but...........that's pushin your luck. I would try and find another integrated head even though they are problematic...
beamn7 is offline   Reply With Quote
Old 01-13-2014, 10:31 AM   #9
moregrip
Registered User
 
moregrip's Avatar
 
Join Date: Dec 2008
Location: Las Vegas, NV
Posts: 810
Re: 79 GMC 4.1L 250 Cylinder Head Advise

I'm sort of hodgepodging a few trucks together to make one....long story short.....I started with an integrated head 250L6 motor and am now switching to a non integrated 194 head as a result of speaking with Tom Langdon........in a nut shell, he believed if the integrated head didn't already have a crack, it would soon would.
__________________

1983 Chevy C10 250/3spd (current project truck)
1976 Chevy C10 350/350 Heavy Half (future project truck)
moregrip is offline   Reply With Quote
Old 01-13-2014, 11:17 AM   #10
Warrens69GMC
Registered User
 
Warrens69GMC's Avatar
 
Join Date: Jan 2003
Location: Safford,AZ
Posts: 3,625
Re: 79 GMC 4.1L 250 Cylinder Head Advise

I have a 331184 on a 250ci that I bought in a 1979 nova. You might want to look for that part # .
__________________
1969 307, t350
1950 Chevy Wagon
1978 Big 10
1967 C10, 250,3-OTT
Warrens69GMC is offline   Reply With Quote
Old 01-13-2014, 03:39 PM   #11
79GMCSierra
Registered User
 
79GMCSierra's Avatar
 
Join Date: Dec 2013
Location: Folsom, CA
Posts: 17
Re: 79 GMC 4.1L 250 Cylinder Head Advise

Quote:
Originally Posted by beamn7 View Post
My 78 federal emissions C10 has the non-integrated head / 1bbl carb. Truck has been in the family since factory order and has 250K miles on her. Never been apart. Great engines! I would imagine you could swap it to a non-integrated and hope the smog guy is too young to even know what a L6 is but...........that's pushin your luck. I would try and find another integrated head even though they are problematic...
When I took it to the smog shop last week the young guy there couldn't figure out how to shift it. It's 3-sp on the floor. He keep putting it into reverse LOL!!

I see you live in California, and your 79 Chevy C10 non-intergated head passed smog I take it.

Does your engine have these items pictured below. The vacuum valve is attached to the detachable header, so I may be able to find a non-intergrated header with that smog valve. For some reason it rotated the pics when I uploaded them.

Quote:
Originally Posted by moregrip View Post
I'm sort of hodgepodging a few trucks together to make one....long story short.....I started with an integrated head 250L6 motor and am now switching to a non integrated 194 head as a result of speaking with Tom Langdon........in a nut shell, he believed if the integrated head didn't already have a crack, it would soon would.
Yup like the the machine shop guy said "It's a mistake"

Quote:
Originally Posted by Warrens69GMC View Post
I have a 331184 on a 250ci that I bought in a 1979 nova. You might want to look for that part # .
Thanks Warren I'll kook for that part number!

Thanks all! Jim
Attached Images
  

Last edited by 79GMCSierra; 01-13-2014 at 03:40 PM. Reason: Spelling
79GMCSierra is offline   Reply With Quote
Old 01-13-2014, 04:52 PM   #12
powerdriver 1958
Kid's Mechanic
 
powerdriver 1958's Avatar
 
Join Date: Nov 2006
Location: Kansas City
Posts: 8,241
Re: 79 GMC 4.1L 250 Cylinder Head Advise

When you get ready to remove the integrated head , Have an extra set of hands close . I weighed mine and it was 142 lbs .
powerdriver 1958 is offline   Reply With Quote
Old 01-13-2014, 05:41 PM   #13
79GMCSierra
Registered User
 
79GMCSierra's Avatar
 
Join Date: Dec 2013
Location: Folsom, CA
Posts: 17
Re: 79 GMC 4.1L 250 Cylinder Head Advise

Quote:
Originally Posted by powerdriver 1958 View Post
When you get ready to remove the integrated head , Have an extra set of hands close . I weighed mine and it was 142 lbs .
YIPES!!! Good call!
79GMCSierra is offline   Reply With Quote
Old 01-16-2014, 12:43 PM   #14
beamn7
Registered User
 
Join Date: Oct 2011
Location: Wildomar, CA
Posts: 466
Re: 79 GMC 4.1L 250 Cylinder Head Advise

Quote:
Originally Posted by 79GMCSierra View Post
When I took it to the smog shop last week the young guy there couldn't figure out how to shift it. It's 3-sp on the floor. He keep putting it into reverse LOL!!

I see you live in California, and your 79 Chevy C10 non-intergated head passed smog I take it.

Does your engine have these items pictured below. The vacuum valve is attached to the detachable header, so I may be able to find a non-intergrated header with that smog valve. For some reason it rotated the pics when I uploaded them.



Yup like the the machine shop guy said "It's a mistake"



Thanks Warren I'll kook for that part number!

Thanks all! Jim
Yep! It's actually a 78 but yes, it does have the EGR valve and the charcoal cannister you posted in your pics. Difference also though is that the non-integrated heads use a single exhaust outlet manifold whereas the integrated head on yours has the dual outlets. Having said that, you would also need some exhaust work if you were to change it over.

Mines a 3 spd also (back on the column again) and sometimes I think that's the best theft deterrent around. Nobody knows how to drive them anymore!
beamn7 is offline   Reply With Quote
Old 01-16-2014, 02:59 PM   #15
79GMCSierra
Registered User
 
79GMCSierra's Avatar
 
Join Date: Dec 2013
Location: Folsom, CA
Posts: 17
Re: 79 GMC 4.1L 250 Cylinder Head Advise

Quote:
Originally Posted by beamn7 View Post
Yep! It's actually a 78 but yes, it does have the EGR valve and the charcoal cannister you posted in your pics. Difference also though is that the non-integrated heads use a single exhaust outlet manifold whereas the integrated head on yours has the dual outlets. Having said that, you would also need some exhaust work if you were to change it over.

Mines a 3 spd also (back on the column again) and sometimes I think that's the best theft deterrent around. Nobody knows how to drive them anymore!
Yup every time I've taken it somewhere for service I've had to coach them on how to shift it!

Last edited by 79GMCSierra; 01-16-2014 at 03:00 PM. Reason: spelling
79GMCSierra is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 10:28 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com