C3 Dewitt Rad frame

[Michael B.]

A friend and supplier of parts once said to me he did not like using retrofits of anything. He was not a purist, but in his words "change one thing, change 10 things"; in other words, even changing "drop-in" retrofits usually mean lots of other unintended alterations.

For those interested in the Dewitt rad kit (the frame that comes with the aluminum rad for the C3) it is not an exact match for the 77 frame. Before you try to install the hood/hinge you will need to cut the frame at an angle to match the original. Without this mod one of the bolts of the right hinge will interfere with the hood on closing.

Make a template of the original and shape as required.
Cheers,

Michael B.

[Joe L.]

Re: C3 Dewitt Rad frame

A friend and supplier of parts once said to me he did not like using retrofits of anything. He was not a purist, but in his words "change one thing, change 10 things"; in other words, even changing "drop-in" retrofits usually mean lots of other unintended alterations.

For those interested in the Dewitt rad kit (the frame that comes with the aluminum rad for the C3) it is not an exact match for the 77 frame. Before you try to install the hood/hinge you will need to cut the frame at an angle to match the original. Without this mod one of the bolts of the right hinge will interfere with the hood on closing.

Make a template of the original and shape as required.
Cheers,

Michael B.

Michael------


I don't think that DeWitts actually manufactures the radiator supports ("frames"). I think they are likely manufactured by Coffman Corvette. That's the only manufacturing source I know of although Vette Products of Michigan may also manufacture these.

I have heard of some fitment problems with the Coffman-manufactured supports. However, they're one of the few, if not only, manufacturer of these things. In any event, Coffman is very conscientious about their products. I would think that they would have worked problems as you describe out of their products by now.

[Michael B.]

Re: C3 Dewitt Rad frame

Hi Joe,

The posting was not meant to sound like a complaint rather just a bit of guidance to fellow members. I installed the rad over a year ago when I was testing the motor. As I am working the body now and everything is (almost) ready to glue down, there is nothing worse than finding out this late you have another tweak to do. (Just image the joy when I realized why the hood would not close properly).

It's also guidance to everyone - NEVER throw anything out until the project is complete !!!
I have the old rotted rad frame and am using this to make a template to shave off a couple inches of the frame, but of course this will be done in-place now.

I have no doubt Dewitt and their supplier are responsible companies. These "subtle" differences are not so subtle when everything is locked in place. It would also have helped to know in advance that the clearance between the lower hose and the stabilizer bar drops to below the spec. Instead of a minimum (when include the +/- variance) of about 0.45" I now drop to about 0.25" because of the far thicker aluminum core. The plastic shroud for the fan also had to be shaved about 1/4 inch to accommodate the upper A-arm forward retainer but this must be marked in place and may not be exactly the same for every car. Dewitt or SPAL could fix this by cutting a small notch.

Thanks as always for the feedback.

Michael B.

[Joe L.]

Re: C3 Dewitt Rad frame

Hi Joe,

The posting was not meant to sound like a complaint rather just a bit of guidance to fellow members. I installed the rad over a year ago when I was testing the motor. As I am working the body now and everything is (almost) ready to glue down, there is nothing worse than finding out this late you have another tweak to do. (Just image the joy when I realized why the hood would not close properly).

It's also guidance to everyone - NEVER throw anything out until the project is complete !!!
I have the old rotted rad frame and am using this to make a template to shave off a couple inches of the frame, but of course this will be done in-place now.

I have no doubt Dewitt and their supplier are responsible companies. These "subtle" differences are not so subtle when everything is locked in place. It would also have helped to know in advance that the clearance between the lower hose and the stabilizer bar drops to below the spec. Instead of a minimum (when include the +/- variance) of about 0.45" I now drop to about 0.25" because of the far thicker aluminum core. The plastic shroud for the fan also had to be shaved about 1/4 inch to accommodate the upper A-arm forward retainer but this must be marked in place and may not be exactly the same for every car. Dewitt or SPAL could fix this by cutting a small notch.

Thanks as always for the feedback.

Michael B.

Michael------


Are you using a DeWitt's "Direct Fit" aluminum radiator or are you using something else? I have found that their 69-72 big block "Direct Fit" radiator is dimensionally virtually identical to the 69-72 big block copper/brass radiator and also very close configurationally. I would think that the 1977 radiator would be, too, since it's, basically, the same radiator as the 69-72 big block except with an integral filler neck.

[Michael B.]

Re: C3 Dewitt Rad frame

Hi Joe,

I pulled up my original order from Dec 08.

It is the
DIRECT FIT ALUMINUM RADIATOR WITH FAN
It's not the same size as the original core for the 77 L48. It definitely is more the size of a big block rad. The note I see from CC is - "This radiator uses cushions part # 243081, for both L48 and L82 applications", which was ordered at the same time.

But in checking the order the rad frame it not from Dewitt. It's a Corvette Central part and was listed as late model 76 to 81. Because everything came together on this order I misspoke in stating this was part of the Dewitt kit which was just the rad with fan attached.

Thanks for keeping me honest.

Michael B.