Upper rad hose quiz? DO YOU KNOW? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Durney · 01-24-2003, 11:25 AM

Once again after talking to some of the "dealers/experts" from these pages there is a disagreement.

Did ALL 4WD small blocks use the metal tube in the upper radiator hose or was it only the early 67/68 3/4 ton?

Also does anyone have the metal "intermediate" tube?

your opinions are welcome - but facts are better - thanks!

(I am still surprised by the lack of concrete research that has been done on these trucks versus the normal musclecars... especially knowing the massive interest)

**JIMs70GMC** · 01-24-2003, 11:36 AM

MY GMC w/ 350 has a one piece upper rad hose. When I went to replace it I had to get one for a 2wd.

gman · 01-24-2003, 11:53 AM

I have the metal tube for my upper radiator hose......cut to fit hose on both ends........approx 4 inches on intake side, 7 inches on radiator inlet side.

I've got a '72 K10 SWB and I seriously doubt the old man I bought it from would've bothered getting one from some other truck. I have yet to find anything on the truck I bought that wasn't original from the factory other than the plastic bed liner.

Seems like most people don't have them anymore. It gets replaced with the one piece hose. The hoses on my truck were so old they broke into pieces when I replaced them.

mrein3 · 01-24-2003, 01:46 PM

When I bought my truck it had the metal pipe for the upper hose. I replaced it with a one-piece rubber hose. Now the metal one is my spare for if/when I blow it on the road.

Some time in the future I'm going to paint the metal one up real nice, buy new rubber "ends" and install it back on the engine.

da-burb · 01-24-2003, 02:09 PM

of the 5 4x4's I have, all are 71's and 72's, all have the metal tube.

gman · 01-24-2003, 02:13 PM

5?

That sounds like you are gloating.

No gloating allowed here..:p
(if you only knew how jealous I am)

Durney · 01-24-2003, 02:15 PM

Now thats HARD data! As I thought, it looks like all the 4X4's had it. Great!

Now can someone post a pic of one or has one for sale thats in nice shape? What material was it?

thanks guys!

mrein3 · 01-24-2003, 02:33 PM

If da-burb doesn't beat me to it I'll snap a picture tomorrow. Tonight is Gopher puck night so I won't be home until way after bedtime.

Go Gophers!

(And sorry. Mine is not for sale.)

**Classic Heartbeat** · 01-24-2003, 02:56 PM

All of the 4X4s had the steel radiator hose tube. You can go to your nearest muffler shop and have them bend you one out of nickle-ized aluminum exhaust pipe. WES www.Classicheartbeat.com

DMAN · 01-24-2003, 03:10 PM

That's what mine looks like.

*dtlilly* · 01-24-2003, 03:17 PM

What I don't all learn here. What is the diameter of the bent exhaust pipe. Thanks, Don

**Classic Heartbeat** · 01-24-2003, 03:22 PM

1 1/2" works.... WES www.ClassicHeartbeat.com

Durney · 01-24-2003, 03:48 PM

Outstanding, Thanks Wes.

But, are you sure the original is steel? It seems there would be a problem with electolysys. The muffler moly is typically galvanized and may make the electrolysis even worse as it reacts with the ethylene-glycol. Now I think you might be safe if you used the new Dexcool thats designed to fight ecectrolysis and work better with aluminum.

The other issue is if someone uses the local tube bender it will shrink the radiuses (assuming its not a mandrel bender) and both cause a restiction (not a big deal) and certainly not look original (to me a big deal with a resto)

Finally, do these have a raised edge under the hoses ?

**Yukon Jack** · 01-24-2003, 03:51 PM

Here's the metal tube that was used on my 307 in my K20.

gman · 01-24-2003, 03:57 PM

Original is definitely steel. Can't recall for sure but I don't believe it had a raised edge. I just replaced hose couple weeks ago.

**Classic Heartbeat** · 01-24-2003, 04:06 PM

The origanals are steel and electrolisis was and still is a problem with them. You can go two ways with exhaust pipe though and not have galvinized. One is nickle-ized aluminum and the other is more expencive, but worth it and that is stainless steel. WES www.ClassicHeartbeat.com

Duallie · 01-25-2003, 11:52 PM

Yes, the tubes were beaded on the ends.

Dan72cst · 01-26-2003, 12:06 AM

72 blazer 4x4 came with one

Lippyp · 01-26-2003, 07:40 AM

My 67 2wd witha 350 in the six position has a piece of exhaust in the middle of the upper rad hose, but I think it's because the previous owner couldn't find the right hose and made one up out of two bits, still it works well enough for the moment.

Durney · 01-26-2003, 09:53 AM

If anyone has an extra one laying around I sure could use it!

Thanks - hellcat@provide.net

71k5 · 01-26-2003, 10:40 AM

My '71 Blazer came with the metal center section, too.

Bob Chayer · 01-26-2003, 11:02 AM

71 Suburban 4X4 w/307 and 72K20 w/350 both have the metal tube. Both are weak though.

**jerry moss** · 01-26-2003, 11:13 AM

all 4 of my K-20s have them. i work in a muffler shop and the tubing we use is aluminized steel. several years ago i started building those out of stainless steel tubing, just never finished any of them. they are bent but need the bead on the ends. stainless is expensive but most muffler shops should be able to get it in 7 foot lengths. if you get the tubing yourself, be careful as some is NOT bendable. it will crush if you try to bend it.

ckhd · 01-26-2003, 09:12 PM

My '68 K20 has a metal upper tube.
My '69 K10 has a metal upper tube.
My '72 K10 Suburban has a metal upper tube.

My understanding is that it is a "K" thing.

01-24-2003, 11:25 AM	#1
Durney Registered User Join Date: Jul 2002 Location: Michigan Posts: 158	Upper rad hose quiz? DO YOU KNOW? Once again after talking to some of the "dealers/experts" from these pages there is a disagreement. Did ALL 4WD small blocks use the metal tube in the upper radiator hose or was it only the early 67/68 3/4 ton? Also does anyone have the metal "intermediate" tube? your opinions are welcome - but facts are better - thanks! (I am still surprised by the lack of concrete research that has been done on these trucks versus the normal musclecars... especially knowing the massive interest)

01-24-2003, 11:36 AM	#2
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	MY GMC w/ 350 has a one piece upper rad hose. When I went to replace it I had to get one for a 2wd. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

01-24-2003, 11:53 AM	#3
gman Registered User Join Date: Nov 2000 Location: Ogden, Utah Posts: 290	I have the metal tube for my upper radiator hose......cut to fit hose on both ends........approx 4 inches on intake side, 7 inches on radiator inlet side. I've got a '72 K10 SWB and I seriously doubt the old man I bought it from would've bothered getting one from some other truck. I have yet to find anything on the truck I bought that wasn't original from the factory other than the plastic bed liner. Seems like most people don't have them anymore. It gets replaced with the one piece hose. The hoses on my truck were so old they broke into pieces when I replaced them. __________________ 72 Chevy SWB Custom Deluxe K10, 350/SM465, PS, PB, Fact. Air 2000 Harley...Wide Glide

01-24-2003, 01:46 PM	#4
mrein3 Registered User Join Date: Feb 2000 Location: Center City, MN, USA Posts: 3,253	When I bought my truck it had the metal pipe for the upper hose. I replaced it with a one-piece rubber hose. Now the metal one is my spare for if/when I blow it on the road. Some time in the future I'm going to paint the metal one up real nice, buy new rubber "ends" and install it back on the engine. __________________ '70 cab, '71 chassis, 383, TH350, NP205. '71 Malibu convertible '72 Malibu hard top Center City, MN

01-24-2003, 02:09 PM	#5
da-burb "Ochre Ogre" Join Date: Apr 2000 Location: Springfield, MN Posts: 3,558	of the 5 4x4's I have, all are 71's and 72's, all have the metal tube. __________________ Bowtie Truck Stop Inc. Mid-West GM Truck Restoration Parts Supplier Your Key Parts, Auto Metal Direct, Dynacorn, and Goodmark dealer. like us @ www.facebook.com/BowtieTruckStop 1971 C-10 Suburban (Ochre) 1971 K-10 Suburban (Ochre) 1972 C-10 Suburban (Ochre) 1972 K-20 Suburban (Yellow- that just aint right!) Springfield, Minnesota 56087

01-24-2003, 02:13 PM	#6
gman Registered User Join Date: Nov 2000 Location: Ogden, Utah Posts: 290	5? That sounds like you are gloating. No gloating allowed here..:p (if you only knew how jealous I am) __________________ 72 Chevy SWB Custom Deluxe K10, 350/SM465, PS, PB, Fact. Air 2000 Harley...Wide Glide

01-24-2003, 02:15 PM	#7
Durney Registered User Join Date: Jul 2002 Location: Michigan Posts: 158	Now thats HARD data! As I thought, it looks like all the 4X4's had it. Great! Now can someone post a pic of one or has one for sale thats in nice shape? What material was it? thanks guys!

01-24-2003, 02:33 PM	#8
mrein3 Registered User Join Date: Feb 2000 Location: Center City, MN, USA Posts: 3,253	If da-burb doesn't beat me to it I'll snap a picture tomorrow. Tonight is Gopher puck night so I won't be home until way after bedtime. Go Gophers! (And sorry. Mine is not for sale.) __________________ '70 cab, '71 chassis, 383, TH350, NP205. '71 Malibu convertible '72 Malibu hard top Center City, MN

01-24-2003, 02:56 PM	#9
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,770	All of the 4X4s had the steel radiator hose tube. You can go to your nearest muffler shop and have them bend you one out of nickle-ized aluminum exhaust pipe. WES www.Classicheartbeat.com __________________ On-line catolog Classic Heartbeat Pickup Parts WEHEPP@comcast.net Call us Toll Free (888) 338-2502 Like Us on Facebook No appointment necessary. 72 BB Chevy Custom Deluxe / Custom Camper 67 I-6 (Soon to be 5.7 LS1) Panel 68 BB Chevy Short Bed 72 6.0 LQ9 Short Bed Chevy 4X4 Olympia's fastest growing truck parts supplier. Olympia's home for Wayward Chevys Last edited by Classic Heartbeat; 10-04-2007 at 06:48 PM.

01-24-2003, 03:10 PM	#10
DMAN Registered User Join Date: May 2002 Location: Benicia,Ca. Posts: 128	That's what mine looks like. __________________ '71 Custom Deluxe K10, shortbed, fleetside.

01-24-2003, 03:17 PM	#11
dtlilly Account Suspended Join Date: Jan 2003 Location: Shadow of Lambeau Field Posts: 5,597	Thats a good idea What I don't all learn here. What is the diameter of the bent exhaust pipe. Thanks, Don

01-24-2003, 03:22 PM	#12
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,770	1 1/2" works.... WES www.ClassicHeartbeat.com __________________ On-line catolog Classic Heartbeat Pickup Parts WEHEPP@comcast.net Call us Toll Free (888) 338-2502 Like Us on Facebook No appointment necessary. 72 BB Chevy Custom Deluxe / Custom Camper 67 I-6 (Soon to be 5.7 LS1) Panel 68 BB Chevy Short Bed 72 6.0 LQ9 Short Bed Chevy 4X4 Olympia's fastest growing truck parts supplier. Olympia's home for Wayward Chevys

01-24-2003, 03:48 PM	#13
Durney Registered User Join Date: Jul 2002 Location: Michigan Posts: 158	Outstanding, Thanks Wes. But, are you sure the original is steel? It seems there would be a problem with electolysys. The muffler moly is typically galvanized and may make the electrolysis even worse as it reacts with the ethylene-glycol. Now I think you might be safe if you used the new Dexcool thats designed to fight ecectrolysis and work better with aluminum. The other issue is if someone uses the local tube bender it will shrink the radiuses (assuming its not a mandrel bender) and both cause a restiction (not a big deal) and certainly not look original (to me a big deal with a resto) Finally, do these have a raised edge under the hoses ?

01-24-2003, 03:51 PM	#14
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,683	Here's the metal tube that was used on my 307 in my K20. Attached Images __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14

01-24-2003, 03:57 PM	#15
gman Registered User Join Date: Nov 2000 Location: Ogden, Utah Posts: 290	Original is definitely steel. Can't recall for sure but I don't believe it had a raised edge. I just replaced hose couple weeks ago. __________________ 72 Chevy SWB Custom Deluxe K10, 350/SM465, PS, PB, Fact. Air 2000 Harley...Wide Glide



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01-24-2003, 04:06 PM	#16
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,770	The origanals are steel and electrolisis was and still is a problem with them. You can go two ways with exhaust pipe though and not have galvinized. One is nickle-ized aluminum and the other is more expencive, but worth it and that is stainless steel. WES www.ClassicHeartbeat.com __________________ On-line catolog Classic Heartbeat Pickup Parts WEHEPP@comcast.net Call us Toll Free (888) 338-2502 Like Us on Facebook No appointment necessary. 72 BB Chevy Custom Deluxe / Custom Camper 67 I-6 (Soon to be 5.7 LS1) Panel 68 BB Chevy Short Bed 72 6.0 LQ9 Short Bed Chevy 4X4 Olympia's fastest growing truck parts supplier. Olympia's home for Wayward Chevys

01-25-2003, 11:52 PM	#17
Duallie Registered User Join Date: Feb 2001 Location: Nikiski, Alaska Posts: 477	Yes, the tubes were beaded on the ends. __________________ Just as if I knew what I was doin'

01-26-2003, 12:06 AM	#18
Dan72cst Registered User Join Date: Feb 2001 Location: Lake Stevens,WA 98258 North of Seattle Posts: 833	72 blazer 4x4 came with one __________________ Marysville, WA (Dan72cst@hotmail.com) 72 4wd Blazer CST 350/350 72 4wd Chevy LWB 350/350 68 2wd Chevy LWB 327/400

01-26-2003, 07:40 AM	#19
Lippyp English Chevy Owner Join Date: May 2002 Location: Shropshire, UK/ Lot, France Posts: 1,848	My 67 2wd witha 350 in the six position has a piece of exhaust in the middle of the upper rad hose, but I think it's because the previous owner couldn't find the right hose and made one up out of two bits, still it works well enough for the moment. __________________ Phil '67 C10 long fleet. 350/TH350, 4 bbl Carter, K&N, Dual exhaust, loads of stuff coming soon 2001 S10 Blazer Daily Driver, bone stock 4 door 4x4 with manual transmission

01-26-2003, 09:53 AM	#20
Durney Registered User Join Date: Jul 2002 Location: Michigan Posts: 158	If anyone has an extra one laying around I sure could use it! Thanks - hellcat@provide.net

01-26-2003, 10:40 AM	#21
71k5 Registered User Join Date: Feb 2002 Location: Manchester, PA Posts: 138	My '71 Blazer came with the metal center section, too.

01-26-2003, 11:02 AM	#22
Bob Chayer Registered User Join Date: Dec 2002 Location: Mid, NH Posts: 150	71 Suburban 4X4 w/307 and 72K20 w/350 both have the metal tube. Both are weak though. __________________ Bob Chayer 71 3/4 ton 4X4 Suburban

01-26-2003, 11:13 AM	#23
jerry moss Born Psycho Join Date: Feb 2001 Location: brentwood,cal,usa Posts: 4,781	all 4 of my K-20s have them. i work in a muffler shop and the tubing we use is aluminized steel. several years ago i started building those out of stainless steel tubing, just never finished any of them. they are bent but need the bead on the ends. stainless is expensive but most muffler shops should be able to get it in 7 foot lengths. if you get the tubing yourself, be careful as some is NOT bendable. it will crush if you try to bend it. __________________ jerry moss 72 cheyenne super K20- tilt,tach,vacuum,speedwarning,buckets,shoulder belts,am/fm,tow hooks,bumper guards,toolbox,aux. fuel tank,posi front and rear,plus other goodies!!! SOLD 69 suburban K20-tilt,tach,vacuum,speedwarning,buckets,shoulder belts,am/fm,4 inch all spring lift,4 speed, 14 bolt full floater, dana 44 HD,warn winch,posi front and rear,tow hooks,plus other goodies. 73/80 chevy/gmc K20 SB400,turbo 400,205,tilt,a-c,gas hog. 77 K/5 cheyenne blazer-daily driver/beater. SON HAS IT NOW BRENTWOOD,CALIFORNIA

01-26-2003, 09:12 PM	#24
ckhd Registered User Join Date: Oct 2000 Location: St. Johns, Arizona Posts: 2,660	My '68 K20 has a metal upper tube. My '69 K10 has a metal upper tube. My '72 K10 Suburban has a metal upper tube. My understanding is that it is a "K" thing. __________________ my 2¢ - t.i.o.l.i. Bowen 1968 K20 fleet 1969 K10 swb fleet 1972 K10 Suburban 1972 C10 lwb step 1992 K1500 'burb 1995 K2500 'burb 1997 C1500 'burb 1999 K1500 2000 K1500 'burb Why do I own so many Suburbans?

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