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skokie · 07-03-2005, 04:45 PM

Are the water ports in the back of a 350 blocked off?

Thanks

**Palf70Step** · 07-03-2005, 07:23 PM

So GM's cheap intake gaskets will fail and you have to get them replaced or replaced the runied engine.

Sarcasim aside, I wish I knew the reason other than what was just stated.

*wolfthing2000* · 07-03-2005, 09:14 PM

I believe this has something to do with manifold warm up and some 350s are diff. than say a truck 350. I don't know for sure but I remember reading something about this.

Sweet72 · 07-03-2005, 10:34 PM

I guess I don't quite understand your question. Are you referring to the expansion (freeze) plugs?

skokie · 07-04-2005, 12:53 AM

Sweet72. I am talking about the ports circled in red.

72gord · 07-04-2005, 07:59 AM

My guess is that the heads will interchange from side to side, so they have a water jacket port on each end so if you put the head on the other side it will have a port in the front. That way GM only had to have one casting for the heads, instead of having lefts and rights. Just a guess, make sense?

Zeke · 07-04-2005, 08:15 AM

so the heads interchange left/right and force coolant through each head to the front then into manifold to radiator. If it crossed in the back coolant could take path of least resistance and cause one head to not cool properly.

neonlarry · 07-04-2005, 10:02 AM

Actually you can use the back ports and not the front, that is what I will be doing on my modified LT1 intake (drilled for a distributor and water outlets).

Gordo · 07-04-2005, 11:20 AM

The engine coolant cycle for a stock engine goes like this, the coolant is taken in from bottom of radiator into the pump, then pumped thru both sides of the engine block from front to rear, then pumped up into back end of the heads, thru the heads from back to front, then into front of intake and out thermostat housing back into radiator.

07-03-2005, 04:45 PM	#1
skokie Registered User Join Date: Oct 2003 Location: San Jose Ca. Posts: 3,354	Why Are the water ports in the back of a 350 blocked off? Thanks __________________ RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234

07-03-2005, 07:23 PM	#2
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 47,251	So GM's cheap intake gaskets will fail and you have to get them replaced or replaced the runied engine. Sarcasim aside, I wish I knew the reason other than what was just stated. __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!

07-03-2005, 10:34 PM	#4
Sweet72 Registered User Join Date: Nov 2003 Location: Alexandria, VA Posts: 1,534	I guess I don't quite understand your question. Are you referring to the expansion (freeze) plugs? __________________ '72 GMC SWB C1500 Custom, frame-off in progress. 383 SBC, 9:1CR, Comp Cams XE262H, Scat internal balanced crank, Eagle SIR 6" rods, Keith Black dish pistons, Dart Iron Eagle 72/180 heads, Weiand Stealth intake, Stewart stage I water pump, Holley 4bbl vac sec, TH350 with B&M Shift Improver Kit. 12 bolt positraction.

07-04-2005, 12:53 AM	#5
skokie Registered User Join Date: Oct 2003 Location: San Jose Ca. Posts: 3,354	Sweet72. I am talking about the ports circled in red. Attached Images __________________ RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234

07-04-2005, 08:15 AM	#7
Zeke Active Member Join Date: Jun 2002 Location: L.A. Lower Alabama Posts: 453	so the heads interchange left/right and force coolant through each head to the front then into manifold to radiator. If it crossed in the back coolant could take path of least resistance and cause one head to not cool properly. __________________ 1969 C10 350 3spd 1995 GMC 3500 XC 350 dually When Thomas Edison worked late into the night on the electric light, he had to do it by gas lamp or candle. I'm sure it made the work seem that much more urgent. George Carlin

07-03-2005, 09:14 PM	#3
wolfthing2000 Account Suspended Join Date: Oct 2004 Posts: 1,276	I believe this has something to do with manifold warm up and some 350s are diff. than say a truck 350. I don't know for sure but I remember reading something about this.

07-04-2005, 07:59 AM	#6
72gord Never enough time!! Join Date: Mar 2004 Location: sw Wisconsin Posts: 601	My guess is that the heads will interchange from side to side, so they have a water jacket port on each end so if you put the head on the other side it will have a port in the front. That way GM only had to have one casting for the heads, instead of having lefts and rights. Just a guess, make sense?

07-04-2005, 10:02 AM	#8
neonlarry Registered User Join Date: Feb 2002 Location: Vacaville, CA Posts: 2,745	Actually you can use the back ports and not the front, that is what I will be doing on my modified LT1 intake (drilled for a distributor and water outlets). __________________ 70 C/10 Light Red 350/TH350, HEI, Duals w/40 series Flows, 91 seat, LED taillights 99 Pontiac S/C GTP, SLP Ram Air hood, GMPP Konis & springs 95 Neon ACR, MP PCM, AFX UDP, 3.0 CAI

07-04-2005, 11:20 AM	#9
Gordo Registered User Join Date: Jan 2001 Location: Killingworth, CT. USA Posts: 3,378	The engine coolant cycle for a stock engine goes like this, the coolant is taken in from bottom of radiator into the pump, then pumped thru both sides of the engine block from front to rear, then pumped up into back end of the heads, thru the heads from back to front, then into front of intake and out thermostat housing back into radiator. __________________ 1971 C10 swb stepside 350/700R4/3.73posi (retired as of 4/22/03) 1998 S10 short bed 2002 S10 Blazer 1942 Oldsmobile 1958 Massey Harris Pony 1951 Wife Killingworth, Connecticut May those who love us, love us, any of those who do not love us, may God turn their hearts. And if God is unable to turn their hearts, may he turn their ankles so we may know them by their limping. A man who works with his hands is a laborer; a man who works with his hands and his brain is a craftsman; but a man who works with his hands and his brain and his heart is an artist.



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