I am upgrading the radiator from a stock 350 manual no accessories model to the 350 LT1 model from Dewitt's. I know I need to order a new core support. Are there any other brackets that I need?

When I look at the picture Paragon has for the LT1 support it doesn't show the two lower center brackets with the holes. I only see the outer brackets that hold the radiator. Does anyone know if the core support has all four lower brackets? Do I need the brackets for the top? These aren't in the picture either.

Thanks!!!

 

I just bought a new radiator and radiator support for my 72 LT-1.

Here is the info which I hope might help:

1. Radiator was 26", bigger than the base radiator, but not as big as the BB. Radiator was brass not alum.

2. Radiator support had the 2 U brackets, one on each side at the bottom, for the radiator (these were weld attached) and 2 U brackets at the top each side, these bolted on with 2 bolts. The LT-1 radiator and LT-1 radiator support does not have the 2 supports closer the center with a hole/post support. There is also a center bracket at the top to attach the shroud. The AIM dwg for the base radiator support shows 2 supports at the bottom of the radiator support that look like they work with a "post" support. My 72 LT-1 does not have that old or new.

3. The 72 AIM has a sheet in the back that shows the LT-1 radiator with the 4 U supports only, at each of the 4 corners.

Hope this helps. This is the stock factory setup. DeWitts might be different, do not know.

 

What number rad are you buying? Knowing that I can post you everything you'll need. use the coupon on the weekend sale and you'll save 15 percent off too...

 

Dewitt's number 4139070M (fan radiator combo kit).

 

Thank you this is helpful. Now I need to figure out if I need those middle brackets since my car is not an original LT-1 car.

 

Ok.. I'm on it.. give me a few minutes...

 

Ok.. I think I have this done now.
Radiator Kit. http://willcoxcorvette.com/product_i...ducts_id=27665
Support. http://willcoxcorvette.com/product_i...oducts_id=2570
Support upper rh bracket http://willcoxcorvette.com/product_i...oducts_id=4047
Support upper lh braket http://willcoxcorvette.com/product_i...oducts_id=4046

Mounting cushions needed http://willcoxcorvette.com/product_i...ducts_id=27051

You won't need the top bracket since you'll not be running the fan shround. This bracket in the middle held the shroud in place at the top.

Grille support rod, in case your is toast. http://willcoxcorvette.com/product_i...oducts_id=4415

Seal Kit if desired: http://willcoxcorvette.com/product_i...ducts_id=11174

The lower brackets needed are made on the support... this radiator mounts via the tanks only unlike the small block radiator that mounted off two the two brackets.

 

Thank you, I am ordering the parts from your site. Does this bolt kit include the bolts needed for the upper brackets?

Radiator Support Bolt & Shim Kit. 18 Piece 63-82 $9.99

Part Number: K1329
Part Year: 1963-1982

 

Those are the side bolts.. I don't know why but the link is turned off on the upper bolts.. let me fix that. http://willcoxcorvette.com/product_i...ducts_id=27666

 

rehirsch8: Question for you. Would like to know the width of the opening of your original core support. This would be the inside, horizontal dimension between the filler plates (one driverls side and one pass side). Trying to confirm what I have.

 

22.5" wides between the filler plates.

 

rehirsch8: One question leads to another. What type of radiator are you replacing? If its an original Harrison plate-type, aluminum, I'd like to know the width of the finned section through which you can see daylight.



I've got the Dewitt's repo shown above which measures 21" across the fins (overall width 22.5"). If you have a Harrison, how does it seal against the core support filler plates? Seems to me that the opening is too wide for the radiator. Hope that you can throw some light on this.

 

I'll take a look when I get a chance but my old radiator is at the shop so I don't have easy access to it. I don't know if it is an original radiator or not. My car was a 350 4 speed car with no accessories and it cooled very well on hot days. The only reason I'm changing it is that I'm adding vintage air and refreshed the motor with higher compression. Once I installed the vintage air condenser on the core support it covered the entire small radiator. I don't know whether it would have worked okay or not but my wife says she doesn't want to find out the hard way on a hot day this summer.

 

The 68-72 Corvette radiator usage is a little bit confusing, but not too hard to clear up....

All 68-72 small block base cars used the smaller aluminum radiator (3155316) and a separate aluminum surge tank on the fender skirt. This unit mounts on two 1/2" pins on the bottom with round rubber donuts. As mention above Willcox core support would be 25440. A base car is one without any of the following options: Air conditioning, Automatic transmission, or a special motor option like LT1 or L46. If you have any one of these or a combination of them the small block radiator would be the following radiator.

If a 69-72 small block came with automatic, AC, and/or LT1 or L46, then the aluminum radiator was changed to the larger copper/brass radiator. The aluminum surge tank was eliminated because the radiator has a filler neck. The radiator industry referes to this radiator as a 26" core because that is the distance between the headers (mounts). That puts the mounts at about 261/2" center to center. Willcox needs to change the description on this core support (25441) because it was never used on any big block cars.

Big block 69-72 Corvettes used only one radiator, available in automatic and manual options. The core measures 27.5" which puts the mounts about 28" on center to center. This radiator was copper brass, had no filler neck, and used the aluminum surge tank on the fender skirt. Again, Willcox needs to change the description on 25442 because this core support was never used on any small block Corvette.

Confusion happens when people make changes to the factory configuration. The 1973 radiators are identical to the 69-72 BB (27.5) except they have a filler neck and many replacement companies will just sell this one for the earlier models to reduce inventory. Then you have two filler necks or the owner deletes the surge tank as it is no longer needed and that confuses other owners because they thought big block came with surge tanks.

FYI, the two copper supports 25441 (26" SM) and 25442 (27.5" BB) are identical except one item and that is the lower U bracket on the passenger side. It is spot welded on and tough to remove but you can convert one to the other by just moving this bracket in or out. The top left bolt on bracket is the same for both applications while the top right is unique for each unit.

1968 Big block and small blocks with AC or auto used a copper radiator from 1967. It had a core width of 22.5".

Hope this helps someone in the future

 

Thanks Tom & others. The radiator combos for 1969 have always been a mystery until this post. I have a situation where I need to purchase a radiator support & new radiator for my 69 base model no A/C, manual transmission car. Should I just go with the "original" setup or should I consider going with a BB setup for more cooling power since I am essentially starting from scratch? Any thoughts/opinions appreciated.

 

Since you are starting from scratch you could do any one of the three options. There isn't any noticeable difference in cooling from the 26" sb to the 27.5" bb, so the choice here depends if you want to keep the aluminum surge tank. The 26" sb has a filler neck, that would render the tank useless. The 27.5 bb uses the tank and this radiator would provide the maximum cooling of all three choices.

For those that ever questioned the performance of aluminum the above example hows just how good they work. The smaller 18" aluminum radiator cools the V8 fine while the copper/brass radiators need to 50% larger

 

rehirsch8: Awaiting your findings. Thanks for the continued help.

Tom: We appreciate the clarification on an often confusing topic. Hope to get that radiator of yours (ain't it purdy?) installed before driving season is upon us!

 

The fins are 19" wide.