V8 / 700r4 cooling - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**guyryan100** · 10-08-2004, 10:26 PM

I'm upgrading from an I6 to a 350 and from a 3 speed to a 700r4. Can I get by with my current radiator and a big external transmission cooler? I hope not to have to shell out the $ for a new radiator. I'm in GA where it's not too hot.

Thanks all

**Smitty** · 10-09-2004, 09:56 AM

I swapped from a 307 to 350 and the 3-speed like you did. When I bought the 700 I was told that heat and improper tv cable adjusters killed these things. So I put in a 4-core AND a huge aux cooler and run a trany temp guage. Have had it together for about 5 years or so and no problems.

**Palf70Step** · 10-09-2004, 12:08 PM

I don't think the stock 6 popper radiator is big enough. I think they are classified as 2 core. You'll be way ahead paying for the 4 core unit. You'll probably also need to get the V8 shroud instead of the 6's top cover. If you get the 4 core it'll have the collant for your tranny built in and should handle that fine, unless your going to do some HD running or towing. You'll probably end up paying about the same for a good 4 core as you would a aftermarket tranny cooler.

**guyryan100** · 10-09-2004, 12:40 PM

From what could I pull a 4 core radiator that would fit? I assume that radiators haven't changed much over the years

CaperCat · 10-09-2004, 12:49 PM

Look for a truck with a V-8 and air conditioning. They will have the 4-core radiator. A new one costs around $245, so don't spend too much on a used one because you will need to have it boiled out and pressure tested before you install it in your truck. Boiling it costs around $50. It may be less money to get a new one.

I agree with Smitty, get a new 4-core radiator and a big auxiliary cooler and enjoy driving the new engine and transmission. 'Just my $0.02 .

ChevLoRay · 10-09-2004, 04:13 PM

Let's see, a part of Georgia that doesn't get too hot.....

My niece lives near Blue Mountain, GA. From what I saw, if it ain't the heat, it's the hills. Either one could be a strain on your cooling system.

incoma · 10-09-2004, 04:27 PM

I just bought a new 4 core from Autozone for my 70 GMC w/ A/C, auto. #433369 - $178.99 + tax. Radiators.com is a bit cheaper but you have to pay shipping, and in my mind they have an unproven product, as I've bought several autozone radiators and have no problems with them.

cdowns · 10-09-2004, 06:30 PM

to be on the safe side i'd go for the 4core plus an auxillary tranny cooler also. that's what i did with my 2004r

Tx Firefighter · 10-09-2004, 08:15 PM

I've run V8 swaps through the old 6 cylinder radiator here in Texas heat before with no problem.

Radiator.com is your friend if you must buy new. My big 4 core for my 454 truck was 150 bucks delivered.

Longhorn Man · 10-09-2004, 10:58 PM

There were plenty of heavy cars, and trucks, with big v-8 motors and 2 row radiators.
Personally, i would get an inexpensive tranny cooler, and place it right on the back side of the grill, and then drive it with the old rad and cheap cooler. If it overheats, then you know what you need to do. if it don't, then go get a quality cooler...and you can get good coolers for way less than 245 bucks.

**guyryan100** · 10-09-2004, 11:18 PM

Seems there are really two issues here:

1) Will an external cooler alone keep a 700r4 cool?
2) Will the lil' 6cyl radiator keep a 350 cool?

As to #2, I like Longhorn Man's suggestion - try it and see. I guess that way if the engine is running hot I can swap radiators and then have the benefit of the cheep cooler. But to issue #1, will I know if the tranny is getting to hot?

Longhorn Man · 10-10-2004, 12:26 AM

A tranny cooler alone will keep it cooler than a rad tranny cooler.
The one inside a rad will mainrtian the tranny temp at 190 - 200 degrees...which most every rebuilder will tell you is too hot.

chevyhouse · 10-10-2004, 01:27 AM

Quote:

Originally Posted by Longhorn Man

A tranny cooler alone will keep it cooler than a rad tranny cooler.
The one inside a rad will mainrtian the tranny temp at 190 - 200 degrees...which most every rebuilder will tell you is too hot.

I run just the 4-core on my 700 and never see over 150 on the gauge. 150 in the pan equals about 300-350 in the converter unlocked less than 300 if locked. As long as you have a functional lockup curcuit--add one to third if you are towing--a 700r4 is not going to have many heat problems. I got my 4-core auto rad from the local shop for $90, for that price get the better radiator and a temp gauge. Add a cooler later if you need it, just remember that you never want more than 150 in the pan and you will be ok.

**guyryan100** · 10-10-2004, 09:29 AM

Seems 4 core rads are closer to $190 than $90 around here :-(

Tx Firefighter · 10-10-2004, 12:31 PM

Radiator.com

150 bucks for a 4 core delivered next day in the United States

10-09-2004, 12:08 PM	#3
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 46,845	I don't think the stock 6 popper radiator is big enough. I think they are classified as 2 core. You'll be way ahead paying for the 4 core unit. You'll probably also need to get the V8 shroud instead of the 6's top cover. If you get the 4 core it'll have the collant for your tranny built in and should handle that fine, unless your going to do some HD running or towing. You'll probably end up paying about the same for a good 4 core as you would a aftermarket tranny cooler. __________________ 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!

10-09-2004, 12:49 PM	#5
CaperCat Registered User Join Date: Sep 2003 Location: Concord, North Carolina 28027 Posts: 64	Look for a truck with a V-8 and air conditioning. They will have the 4-core radiator. A new one costs around $245, so don't spend too much on a used one because you will need to have it boiled out and pressure tested before you install it in your truck. Boiling it costs around $50. It may be less money to get a new one. I agree with Smitty, get a new 4-core radiator and a big auxiliary cooler and enjoy driving the new engine and transmission. 'Just my $0.02 . __________________ 1971 Cheyenne 1/2 ton 2WD Long Fleet (sold) Steve

10-09-2004, 04:13 PM	#6
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Let's see, a part of Georgia that doesn't get too hot..... My niece lives near Blue Mountain, GA. From what I saw, if it ain't the heat, it's the hills. Either one could be a strain on your cooling system. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

10-09-2004, 06:30 PM	#8
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	to be on the safe side i'd go for the 4core plus an auxillary tranny cooler also. that's what i did with my 2004r __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

10-09-2004, 08:15 PM	#9
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	I've run V8 swaps through the old 6 cylinder radiator here in Texas heat before with no problem. Radiator.com is your friend if you must buy new. My big 4 core for my 454 truck was 150 bucks delivered. __________________ I'm on the Instagram- @Gearhead_Kevin

10-08-2004, 10:26 PM	#1
guyryan100 Registered User Join Date: Sep 2001 Location: Cumming, GA Posts: 470	V8 / 700r4 cooling I'm upgrading from an I6 to a 350 and from a 3 speed to a 700r4. Can I get by with my current radiator and a big external transmission cooler? I hope not to have to shell out the $ for a new radiator. I'm in GA where it's not too hot. Thanks all

10-09-2004, 09:56 AM	#2
Smitty Senior Member Join Date: Dec 1999 Location: Spring Valley, Ca. Posts: 1,112	I swapped from a 307 to 350 and the 3-speed like you did. When I bought the 700 I was told that heat and improper tv cable adjusters killed these things. So I put in a 4-core AND a huge aux cooler and run a trany temp guage. Have had it together for about 5 years or so and no problems. __________________ Smitty '71 Short Fleetside Spring Valley, Ca.

10-09-2004, 12:40 PM	#4
guyryan100 Registered User Join Date: Sep 2001 Location: Cumming, GA Posts: 470	From what could I pull a 4 core radiator that would fit? I assume that radiators haven't changed much over the years

10-09-2004, 04:27 PM	#7
incoma Registered User Join Date: Mar 2004 Location: Lexington, KY Posts: 865	I just bought a new 4 core from Autozone for my 70 GMC w/ A/C, auto. #433369 - $178.99 + tax. Radiators.com is a bit cheaper but you have to pay shipping, and in my mind they have an unproven product, as I've bought several autozone radiators and have no problems with them.

10-09-2004, 10:58 PM	#10
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	There were plenty of heavy cars, and trucks, with big v-8 motors and 2 row radiators. Personally, i would get an inexpensive tranny cooler, and place it right on the back side of the grill, and then drive it with the old rad and cheap cooler. If it overheats, then you know what you need to do. if it don't, then go get a quality cooler...and you can get good coolers for way less than 245 bucks.

10-09-2004, 11:18 PM	#11
guyryan100 Registered User Join Date: Sep 2001 Location: Cumming, GA Posts: 470	Seems there are really two issues here: 1) Will an external cooler alone keep a 700r4 cool? 2) Will the lil' 6cyl radiator keep a 350 cool? As to #2, I like Longhorn Man's suggestion - try it and see. I guess that way if the engine is running hot I can swap radiators and then have the benefit of the cheep cooler. But to issue #1, will I know if the tranny is getting to hot?

10-10-2004, 12:26 AM	#12
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	A tranny cooler alone will keep it cooler than a rad tranny cooler. The one inside a rad will mainrtian the tranny temp at 190 - 200 degrees...which most every rebuilder will tell you is too hot.

10-10-2004, 09:29 AM	#14
guyryan100 Registered User Join Date: Sep 2001 Location: Cumming, GA Posts: 470	Seems 4 core rads are closer to $190 than $90 around here :-(

10-10-2004, 12:31 PM	#15
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Radiator.com 150 bucks for a 4 core delivered next day in the United States __________________ I'm on the Instagram- @Gearhead_Kevin



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