20mercury

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!

MelWff

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

69 Chevy

'72 LT-1 radiators have the integral pressure cap. '72 big block radiators did not...they had the expansion tank. Which do you have?

20mercury

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

MelWff

or the 803 is the correct radiator as supported by 2 web sites and the other sources you sited have typos. Did you click on the links and notice the notes on the bottom of the second link?

Solid LT1

Give forum vendor DeWitts radiator a call, get the right part the first time. If car is original, save the old .radiator, or get a quality re-core of the original.

Easy Mike

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?

Alan 71

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

mark6669

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

0Tom@Dewitt

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

rogman16

Tom--

You DA man...

Rogman

20mercury

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 ???