Radiator Confusion!!
Thread Starter
Safety Car
Joined: May 2008
Posts: 3,751
Likes: 719
From: Lafayette Louisiana
Radiator Confusion!!
I need some radiator education please! 
I got a project 72 LT1, 4sp, no a/c, that has a leaking radiator and trying to figure out what to buy.
My core size is 26x17x2-5/8 and has the GM part number of 3018803, MK9, saddle mount (not pin mount) which according to the Corvette Rolling Chassis/McNicholl book is for a 72 big block V8 and is a copper radiator.
72 LT1 is supposed to have a 3018802.
Questions:
1. Looks like my 72 has a big block radiator and the wrong one?
2. Why not install a big block replacement radiator in my 72 instead of the original design, you get more cooling which is a good thing??
3. If my current radiator support is matched with the 3018803, would the same radiator support work with even a 27x17x2-5/8 big block radiator? How do you measure radiator supports to see if they fit??? I am guessing the outside dimensions are all the same, the body does not change, I hope, so the inside opening must be different and maybe the saddle supports placement???
Much thanks!
I got a project 72 LT1, 4sp, no a/c, that has a leaking radiator and trying to figure out what to buy.
My core size is 26x17x2-5/8 and has the GM part number of 3018803, MK9, saddle mount (not pin mount) which according to the Corvette Rolling Chassis/McNicholl book is for a 72 big block V8 and is a copper radiator.
72 LT1 is supposed to have a 3018802.
Questions:
1. Looks like my 72 has a big block radiator and the wrong one?
2. Why not install a big block replacement radiator in my 72 instead of the original design, you get more cooling which is a good thing??
3. If my current radiator support is matched with the 3018803, would the same radiator support work with even a 27x17x2-5/8 big block radiator? How do you measure radiator supports to see if they fit??? I am guessing the outside dimensions are all the same, the body does not change, I hope, so the inside opening must be different and maybe the saddle supports placement???
Much thanks!
Last edited by 20mercury; Mar 14, 2012 at 11:25 AM.
Race Director
Joined: May 2006
Posts: 18,695
Likes: 2,572
Are you sure about 3018802. I just saw a picture of what it's supposed to look like and it had fittings for an automatic transmission.
http://www.streetperformance.com/par...8097-a70a.html
The radiator you have 3018803 appears to be the correct one.
http://www.streetperformance.com/par...8098-a70m.html
This site says the same as above 802 is for an automatic and 803 is the correct one
http://www.corvetteamerica.com/cf/di...ategoryid=X745
http://www.streetperformance.com/par...8097-a70a.html
The radiator you have 3018803 appears to be the correct one.
http://www.streetperformance.com/par...8098-a70m.html
This site says the same as above 802 is for an automatic and 803 is the correct one
http://www.corvetteamerica.com/cf/di...ategoryid=X745
Last edited by MelWff; Mar 14, 2012 at 11:46 AM.
Thread Starter
Safety Car
Joined: May 2008
Posts: 3,751
Likes: 719
From: Lafayette Louisiana
Thanks for the responses
Thanks for the responses.
No expansion tank on mine, looking like the overflow rubber hose just goes to the ground.
I know mine is a 26x17x2-5/8, 4 row, copper/brass radiator, with 3018803 on the tag brazed on, looks original.
GM parts books downloaded off the C3 site, lists 72 Y (350) W/SP. H/PER (EXC. H.D. 4SP) 3018802. Looks like this one, 3018802 is also for 350 auto's (guessing T.H. is auto??)
and "how to rebuild Corvette rolling chassis/McNicholl" says GM 3018802 is for a 70 to 72 LT1 and a 3018803 is a 72 big block copper radiator.
I am thinking if the saddle support brackets are the right dimension and the opening is ok, that is what is important, unless you are concerned with NCRS originality. And I am wondering why you would not always want to install a big block radiator if you have to replace your radiator?? Who knows po's might have swapped it out or maybe they ran out of '02's on Friday afternoon at StLouis
No expansion tank on mine, looking like the overflow rubber hose just goes to the ground.
I know mine is a 26x17x2-5/8, 4 row, copper/brass radiator, with 3018803 on the tag brazed on, looks original.
GM parts books downloaded off the C3 site, lists 72 Y (350) W/SP. H/PER (EXC. H.D. 4SP) 3018802. Looks like this one, 3018802 is also for 350 auto's (guessing T.H. is auto??)
and "how to rebuild Corvette rolling chassis/McNicholl" says GM 3018802 is for a 70 to 72 LT1 and a 3018803 is a 72 big block copper radiator.
I am thinking if the saddle support brackets are the right dimension and the opening is ok, that is what is important, unless you are concerned with NCRS originality. And I am wondering why you would not always want to install a big block radiator if you have to replace your radiator?? Who knows po's might have swapped it out or maybe they ran out of '02's on Friday afternoon at StLouis
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
Have you checked the AIM to be certain the LT-1 option did not include the big 4 row copper/brass radiator? If so, there would be no surge tank.
What not have your existing radiator recored?
What not have your existing radiator recored?
Team Owner
Joined: Sep 2006
Posts: 31,214
Likes: 4,301
From: Westminster Maryland
Hi,
In looking at the AIM it appears that the LT-! option used the bb, (LS5), core support and a copper radiator, but doesn't give a part number for the radiator from what I see.
Regards,
Alan
In looking at the AIM it appears that the LT-! option used the bb, (LS5), core support and a copper radiator, but doesn't give a part number for the radiator from what I see.
Regards,
Alan
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Drifting
Joined: Oct 2009
Posts: 1,939
Likes: 199
From: Palm Bay Florida
Call Dewitts with specs. they can make a copper brass repro or an alum. replacement both will perform great.If you're not having it NCRS judged, I have never had a leak from the alum. direct fit rad.
Mark
Mark
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
69-72 350 auto tag #MK19 3018802 26" core filler neck
70-72 LT1 and 69-72 L46 manual tag #MK9 3018803
69-72 BB manual tag #MJ9 3018571 27.5" core no filler neck
69-72 BB auto tag #MH9 3019190
You will find correct replacement cores below
http://www.dewitts.com/pages/categor...s.asp?catID=16
or upgrade to aluminum here
http://www.dewitts.com/pages/categor...s.asp?catID=19
70-72 LT1 and 69-72 L46 manual tag #MK9 3018803
69-72 BB manual tag #MJ9 3018571 27.5" core no filler neck
69-72 BB auto tag #MH9 3019190
You will find correct replacement cores below
http://www.dewitts.com/pages/categor...s.asp?catID=16
or upgrade to aluminum here
http://www.dewitts.com/pages/categor...s.asp?catID=19
Last edited by Tom@Dewitt; Mar 14, 2012 at 08:07 PM.
Drifting
Joined: Aug 2003
Posts: 1,868
Likes: 13
From: Mascoutah IL
69-72 350 auto tag #MK19 3018802 26" core filler neck
70-72 LT1 and 69-72 L46 manual tag #MK9 3018803
69-72 BB manual tag #MJ9 3018571 27.5" core no filler neck
69-72 BB auto tag #MH9 3019190
You will find correct replacement cores below
http://www.dewitts.com/pages/categor...s.asp?catID=16
or upgrade to aluminum here
http://www.dewitts.com/pages/categor...s.asp?catID=19
70-72 LT1 and 69-72 L46 manual tag #MK9 3018803
69-72 BB manual tag #MJ9 3018571 27.5" core no filler neck
69-72 BB auto tag #MH9 3019190
You will find correct replacement cores below
http://www.dewitts.com/pages/categor...s.asp?catID=16
or upgrade to aluminum here
http://www.dewitts.com/pages/categor...s.asp?catID=19
Tom--
You DA man...
Rogman
Thread Starter
Safety Car
Joined: May 2008
Posts: 3,751
Likes: 719
From: Lafayette Louisiana
Much thanks for all of the help!
Much thanks for all of the help!
Yes, clicked on the links, very helpful but in conflict with other places I listed.
Thank you Mr DeWitt, outstanding reputation of your products. I will check that out!
Alan, thanks for the AIM reminder, I checked there earlier and could not figure out why the pin mounted, duh!, until I turned over to the LT1 section, page B3, which shows a 3018803 radiator. Do not see the support number but that sheet is dated 4-25-72, my LT1 is a May 72 build so maybe that explains why I have a 318803 I think. Maybe prior 72 LT1's had the 02?? who knows?
Anyway thanks again as I know a little more now than before!
This forum and the people on it are great!!!
BTW, what is typical ball park cost to recore ???
Yes, clicked on the links, very helpful but in conflict with other places I listed.
Thank you Mr DeWitt, outstanding reputation of your products. I will check that out!
Alan, thanks for the AIM reminder, I checked there earlier and could not figure out why the pin mounted, duh!, until I turned over to the LT1 section, page B3, which shows a 3018803 radiator. Do not see the support number but that sheet is dated 4-25-72, my LT1 is a May 72 build so maybe that explains why I have a 318803 I think. Maybe prior 72 LT1's had the 02?? who knows?
Anyway thanks again as I know a little more now than before!
This forum and the people on it are great!!!
BTW, what is typical ball park cost to recore ???
Last edited by 20mercury; Mar 14, 2012 at 09:53 PM.
