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 > General Truck Forums > Engine & Drivetrain

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 12-02-2014, 11:48 PM   #1
clampjockey
Registered User
 
Join Date: Jan 2008
Location: halifax nova scotia
Posts: 32
Vortec swap questions

I recently bought a 71 gmc with no drive train. I have a th350 tranny, going with either 3.08 or 3.73 gears (most likely 3.08), and a rebuilt 350 from a 72 impala, not bored. I picked up a second hand set of 062 vortecs and RPM intake. I have a 375hp 327 cam/lifter set. I am planning on doing this head swap shortly and want to know everything I need and should know before I start.
I plan on buying a new water temp sensor and getting it cut/threaded to fit the head.
I have a set of tbi valve covers and plan to buy gaskets for vortec??
Buying intake gaskets and bolts for vortec.
Rocker arms came with the heads.

My questions are:
Which head gaskets do i use? Do I order a head gasket for a carbed engine or a vortec? Are they the same?
Is there a certain thermostat/housing I should use regarding coolant bypass topic?
Can I use my headbolts from the old engine or do I need vortec head bolts?
Spark plugs for vortec engine??
If there is anything I'm forgetting or should know, I'd appreciate it being brought up. Thanks
clampjockey is offline   Reply With Quote
Old 12-03-2014, 12:21 AM   #2
clampjockey
Registered User
 
Join Date: Jan 2008
Location: halifax nova scotia
Posts: 32
Re: Vortec swap questions

Edit*
Performer intake, not RPM
clampjockey is offline   Reply With Quote
Old 12-03-2014, 12:42 AM   #3
Captainfab
60-66 Nut

 
Join Date: Mar 2007
Location: Coeur d'Alene, Idaho
Posts: 23,246
Re: Vortec swap questions

The head gaskets are the same for all small blocks with a 4" bore. The thermostat housing has nothing to do with the thermostat bypass. I have reused head bolts on several occasions, but new head bolts are a good idea. New GM head bolts can often be found for less than $100.00. You will want spark plugs for the Vortec engine. That will be a starting point and you can adjust from there depending on how they look after running a bit.
__________________
Power Steering Box Adapter Plates For Sale HERE
Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE
Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE
Hydroboost Mounting Plates HERE
Captainfab is offline   Reply With Quote
Old 12-03-2014, 01:01 AM   #4
Acorn
Registered User
 
Join Date: Jul 2013
Location: Winnsboro Texas
Posts: 367
Re: Vortec swap questions

For spark plugs, I use ac delco R44LTS.
Gaskets, don't go cheap, use the fel-pro reusable rubber/metal ones. Especially on the intake. (Can't remember part number off top of my head)
My water pump has a bypass hose that goes to the intake. If yours does not just drill a few small holes in the thermostat. All 350 blocks will have the holes in the block( where the water pump mounts) but the vortec heads do not.
And like captainfab said, new bolts are a good idea.
__________________
The bitterness of poor quality lingers long after the sweetness of a low price is forgotten.
Acorn is offline   Reply With Quote
Old 12-03-2014, 08:29 AM   #5
clampjockey
Registered User
 
Join Date: Jan 2008
Location: halifax nova scotia
Posts: 32
Re: Vortec swap questions

"All 350 blocks will have holes in the block (where the water pump mounts), but the vortec heads do not"
What do you mean by this? Lack of accessory holes? Coolant passages?
clampjockey is offline   Reply With Quote
Old 12-03-2014, 09:38 AM   #6
Acorn
Registered User
 
Join Date: Jul 2013
Location: Winnsboro Texas
Posts: 367
Re: Vortec swap questions

I was talkin about the coolant passages in the block. On the passenger side, there is a hole where the water pump mount that goes thru the block to the deck of the block then thru the head. But the vortec heads do not have a passage there so there is no way for the coolant to circulate. That is why you need some sort of by pass.
Not the best at describing things but I hope this helps.
Do a search. There is a lot of info out there.
__________________
The bitterness of poor quality lingers long after the sweetness of a low price is forgotten.
Acorn is offline   Reply With Quote
Old 12-03-2014, 09:44 AM   #7
clampjockey
Registered User
 
Join Date: Jan 2008
Location: halifax nova scotia
Posts: 32
Re: Vortec swap questions

So I should look for a waterpump that has a hole for a bypass? I will need a new one anyway...if i order one for a vortec engine, will it have this bypass port?
clampjockey is offline   Reply With Quote
Old 12-03-2014, 07:51 PM   #8
Acorn
Registered User
 
Join Date: Jul 2013
Location: Winnsboro Texas
Posts: 367
Re: Vortec swap questions

We'll that is what I did. I just got a water pump for a '96 vortec 350. It has a fitting for the bypass and a longer one for the heater return. But I am running a serpentine belt system. I am also running a GMPP tbi manifold. So I'm not sure how it would work for you depending on your pully and intake system.
I took a couple of bad pics so you can get an idea what I'm talking about. The bypass hose is the small L shaped hose on the pass side of pump going to the front of the intake.
Attached Images
 
__________________
The bitterness of poor quality lingers long after the sweetness of a low price is forgotten.
Acorn is offline   Reply With Quote
Old 12-03-2014, 07:53 PM   #9
Acorn
Registered User
 
Join Date: Jul 2013
Location: Winnsboro Texas
Posts: 367
Re: Vortec swap questions

Name:  image.jpg
Views: 1140
Size:  34.6 KB
__________________
The bitterness of poor quality lingers long after the sweetness of a low price is forgotten.
Acorn is offline   Reply With Quote
Old 12-03-2014, 07:54 PM   #10
Acorn
Registered User
 
Join Date: Jul 2013
Location: Winnsboro Texas
Posts: 367
Re: Vortec swap questions

Name:  image.jpg
Views: 1217
Size:  34.4 KB
__________________
The bitterness of poor quality lingers long after the sweetness of a low price is forgotten.
Acorn is offline   Reply With Quote
Old 12-04-2014, 12:44 AM   #11
clampjockey
Registered User
 
Join Date: Jan 2008
Location: halifax nova scotia
Posts: 32
Re: Vortec swap questions

Could I use the whole serpentine set up from a 98 donor?
clampjockey is offline   Reply With Quote
Old 12-04-2014, 12:45 AM   #12
Captainfab
60-66 Nut

 
Join Date: Mar 2007
Location: Coeur d'Alene, Idaho
Posts: 23,246
Re: Vortec swap questions

Here are a few pics I have of the hole in the block and the Vortec heads compared to the '95 and earlier heads.

The Vortec water pump will be along pump and reverse rotation for use with a serpentine drive. It really wouldn't be difficult to just drill a hole in the passenger side head. Just use a head gasket for a template.
Attached Images
   
__________________
Power Steering Box Adapter Plates For Sale HERE
Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE
Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE
Hydroboost Mounting Plates HERE
Captainfab is offline   Reply With Quote
Old 12-04-2014, 12:55 AM   #13
clampjockey
Registered User
 
Join Date: Jan 2008
Location: halifax nova scotia
Posts: 32
Re: Vortec swap questions

Wouldn't I trap filings in the passages if i drilled into the head? If I did drill it, i assume I wouldn't have to run the bypass hose?

Getting back to the serpentine thing...do you know of any links of swaps doing this? How would I get an alt to work? Would the PS lines from a 98 fit my steering box? Could I run the newer AC compressor too?
clampjockey is offline   Reply With Quote
Old 12-04-2014, 12:59 AM   #14
Acorn
Registered User
 
Join Date: Jul 2013
Location: Winnsboro Texas
Posts: 367
Re: Vortec swap questions

Thanks captainfab! A picture is worth a thousand words. I saw that pic before and was looking everywhere to try and find it again to help explain what I was trying to say to clampjockey a little better.
__________________
The bitterness of poor quality lingers long after the sweetness of a low price is forgotten.
Acorn is offline   Reply With Quote
Old 12-04-2014, 01:02 AM   #15
clampjockey
Registered User
 
Join Date: Jan 2008
Location: halifax nova scotia
Posts: 32
Re: Vortec swap questions

Yes, thank you!...I totally understand what you are saying now.
clampjockey is offline   Reply With Quote
Old 12-04-2014, 01:03 AM   #16
Acorn
Registered User
 
Join Date: Jul 2013
Location: Winnsboro Texas
Posts: 367
Re: Vortec swap questions

For the belt system, do a search on this site. There are several good threads on this. Search for the power steering as well. If you use a newer ps pump all you have to do is change the fitting on the pump with your original one.
__________________
The bitterness of poor quality lingers long after the sweetness of a low price is forgotten.
Acorn is offline   Reply With Quote
Old 12-04-2014, 01:07 AM   #17
Captainfab
60-66 Nut

 
Join Date: Mar 2007
Location: Coeur d'Alene, Idaho
Posts: 23,246
Re: Vortec swap questions

When you're done drilling just blow the head out with compressed air. It is only into the water jacket and a tiny amount isn't going to hurt anything. If you're really worried about it you can put grease on the drill bit or place a magnet close to the location on the head.

The '72 and earlier trucks all came with short water pumps, so when changing to a long water pump, certain factory parts will no longer work. You will need to change your alternator wiring for the CS130/144 alternator. The power steering pump will have Metric with an O-ring fittings and the steering box in your '71 has SAE fittings. You should be able to run the newer AC compressor, but I am not familiar with just what may need to be changed. I would imagine there are several guys over in the '67-'72 message forum that have changed to the serpentine accessory drive that would have more definitive answers for you.
__________________
Power Steering Box Adapter Plates For Sale HERE
Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE
Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE
Hydroboost Mounting Plates HERE
Captainfab is offline   Reply With Quote
Old 12-07-2014, 03:00 AM   #18
68c10owner
Registered User
 
68c10owner's Avatar
 
Join Date: Oct 2003
Location: Carmichael, California
Posts: 3,006
Re: Vortec swap questions

Vortec heads on earlier engiens have been done for years without any issues. This is the first I`ve heard of having to drill any water passage. This is a very simple swap. Aside from requiring a intake with a vortec bolt pattern its a direct swap.
__________________
Anthony
68c10owner is offline   Reply With Quote
Old 01-05-2022, 04:10 AM   #19
pjmoreland
Senior Member
 
pjmoreland's Avatar
 
Join Date: Jan 2005
Location: CA
Posts: 5,243
Re: Vortec swap questions

I'm rebuilding an 880 L31 Vortec engine right now. The water pump passage was already drilled in the block from the factory, so I followed Captainfab's advice and drilled the corresponding hole in the head. I drilled a 3/32" pilot hole and then drilled it out to 1/4", which matches the hole size in the head gasket. The head is less than 1/4" thick in that spot, so it was easy to drill through.
Attached Images
   

Last edited by pjmoreland; 01-05-2022 at 11:59 AM.
pjmoreland is offline   Reply With Quote
Old 01-05-2022, 05:24 PM   #20
Tom
driving is in my blood
 
Tom's Avatar
 
Join Date: Dec 1999
Location: Mesa AZ
Posts: 5,687
Re: Vortec swap questions

Whats the point of this? I've ran vortec heads on a non-roller block. I've run an entire vortec motor in a 79 without using this bypass. So whats its purpose?
__________________
-78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle.
-98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes.
-02 Suburban 4x4: leveled front
-CBR600F4i, CBR600RR, CBR1000RR, and standup skis
DISCLAIMER: I cant spell for the life of me.
Tom is offline   Reply With Quote
Old 01-05-2022, 05:42 PM   #21
pjmoreland
Senior Member
 
pjmoreland's Avatar
 
Join Date: Jan 2005
Location: CA
Posts: 5,243
Re: Vortec swap questions

Quote:
Originally Posted by Tom View Post
Whats the point of this? I've ran vortec heads on a non-roller block. I've run an entire vortec motor in a 79 without using this bypass. So whats its purpose?
It allows a small amount of coolant to circulate when the engine is cold and the thermostat hasn't opened yet. From what I've read, having no coolant circulation during warm-up can cause temperature spikes in the heads. As an alternative, coolant can circulate through the heater core during warm-up, but this doesn't work if you've got A/C with a shutoff valve to the heater core. Most people end up adding a small hose from the front of the intake manifold to the top of the water pump. I thought it would be cleaner to just drill the missing hole instead of adding this extra hose on the front of the engine. Another solution is to drill some holes in the thermostat.
pjmoreland is offline   Reply With Quote
Old 01-06-2022, 06:04 AM   #22
The Rocknrod
Moderator

 
The Rocknrod's Avatar
 
Join Date: Aug 2011
Location: China Spring, TX
Posts: 7,280
Re: Vortec swap questions

I've got a Vortec head roller motor in mine. But my heater valve has a circulating design when it's off to the heater core (Old Air).
The Rocknrod is offline   Reply With Quote
Old 01-06-2022, 06:22 PM   #23
Tom
driving is in my blood
 
Tom's Avatar
 
Join Date: Dec 1999
Location: Mesa AZ
Posts: 5,687
Re: Vortec swap questions

Quote:
Originally Posted by pjmoreland View Post
It allows a small amount of coolant to circulate when the engine is cold and the thermostat hasn't opened yet. From what I've read, having no coolant circulation during warm-up can cause temperature spikes in the heads. As an alternative, coolant can circulate through the heater core during warm-up, but this doesn't work if you've got A/C with a shutoff valve to the heater core. Most people end up adding a small hose from the front of the intake manifold to the top of the water pump. I thought it would be cleaner to just drill the missing hole instead of adding this extra hose on the front of the engine. Another solution is to drill some holes in the thermostat.
Cool, thanks
__________________
-78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle.
-98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes.
-02 Suburban 4x4: leveled front
-CBR600F4i, CBR600RR, CBR1000RR, and standup skis
DISCLAIMER: I cant spell for the life of me.
Tom is offline   Reply With Quote
Old 01-16-2022, 11:27 AM   #24
Accelo
Senior Member
 
Accelo's Avatar
 
Join Date: Mar 2015
Location: washington
Posts: 2,145
Re: Vortec swap questions

Quote:
Originally Posted by clampjockey View Post
I recently bought a 71 gmc with no drive train. 375hp 327 cam/lifter set
I have a th350 tranny, going with either 3.08 or 3.73 gears (most likely 3.08),
You will not like the cam with 3:08 gears. Are you really adding this solid lifter cam to your motor? This is the same cam used in 1969 z28's and is too radical for your combination IMHO. You will also need a stall converter to run this camshaft. Idle speed is 850RPM. I would use the 327-350hp cam. You will be much happier. I have actually ran this 375HP cam in a Camaro back when I didn't know any better. The car would do almost 60MPH in first gear and was a dog. Changed the gearing to a 3:73 and you couldn't tell it was the same motor. GM only used this cam with a manual transmission. You have been given notice of what you are stepping into. Now it's your turn to make a decision to get some on your foot or not.
Cheers.
Accelo is offline   Reply With Quote
Old 01-18-2022, 12:38 AM   #25
pjmoreland
Senior Member
 
pjmoreland's Avatar
 
Join Date: Jan 2005
Location: CA
Posts: 5,243
Re: Vortec swap questions

Quote:
Originally Posted by Accelo View Post
You have been given notice of what you are stepping into. Now it's your turn to make a decision to get some on your foot or not.
Cheers.
Sorry. I brought this old thread back to life.
pjmoreland is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

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 02:34 AM.


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