DeWitts (Yes, again!)

[Edward B.]

I'm tired of fighting the 20+ year old radiator on my 69 L36, and am assuming from all the treads I've read that the DeWitts 1239069M is the way to go.

However, the $555.00 price is way outside my budget, even with the free shipping at SUMMIT RACING.

My car, in the typical Southern California summer (Temecula/Murrieta area) runs 220-230 sometimes and I KNOW I'm destroying the engine. Where I live, 115 to 118 degrees is not uncommon, so that, coupled with the poor cooling on these cars anyway, I need to be reassured that installing this expensive radiator will really bring the temperatures down to normal. Lower than normal would be even nicer!

Everyone seems to rave about these radiators, but I'm not convinced. Convince me!

Ed

[Joe L.]

Re: DeWitts (Yes, again!)

I'm tired of fighting the 20+ year old radiator on my 69 L36, and am assuming from all the treads I've read that the DeWitts 1239069M is the way to go.

However, the $555.00 price is way outside my budget, even with the free shipping at SUMMIT RACING.

My car, in the typical Southern California summer (Temecula/Murrieta area) runs 220-230 sometimes and I KNOW I'm destroying the engine. Where I live, 115 to 118 degrees is not uncommon, so that, coupled with the poor cooling on these cars anyway, I need to be reassured that installing this expensive radiator will really bring the temperatures down to normal. Lower than normal would be even nicer!

Everyone seems to rave about these radiators, but I'm not convinced. Convince me!

Ed

Ed-------


This is absolutely my radiator of choice for any 1969-72 big block application. It's configuration is very close to original. It has more cooling capacity than any radiator EVER originally installed in a Corvette from 1953 to 2015. In fact, I'm using one in my "ZL-1" application even though I have 2 NOS GM #3019190 and 2 NOS GM #3007436 radiators in my collection [none for sale]. I can't tell you how well it works since I have not run the car yet. However, I'm VERY confident it will work great.

Other than the NOS radiators and DeWitt reproductions of the 3007436, there is absolutely NO other radiator that I would use for a 1969-72 big block. None. Period.

[Loren L.]

Re: DeWitts (Yes, again!)

Two questions: 1> have you verified the temperatures on the gauge with an outside check?; 2> Why buy from a middle-man?

[Harry S.]

Re: DeWitts (Yes, again!)

I agree with Joe!!!!! There is no other option......

[Curt S.]

Re: DeWitts (Yes, again!)

I just helped install a Be Cool radiator in a Copo big block 69 camaro. I was amazed how well it fit where it was supposed to and how very original it looked for the application. It is doing a wonderful job cooling and looks very real. I do not know how these would judge ,but for a very original look that works you may want to contact Be Cool and ask your questions. Good luck in your search. Curt

[Edward B.]

Re: DeWitts (Yes, again!)

Thanks guys. I'll admit the DeWitts is a nice radiator, but I'm just afraid that once it's installed I'll have the same issues. I would hate to spend that much money on something that wouldn't resolve the issue.

I've rodded the old one twice in two years (from a local radiator shop), but it still doesn't do the job so I guess it's time to get something else. I think it's just worn out and has lost most of its cooling ability.

Yes, I've taken readings with my IR gun and it actually jibes with the gauge (which is surprising since most gauges aren't that accurate). I've adjusted the timing to help, but even with that, the car still runs very hot when running around town in the heat of the summer. The fan clutch is new and the fan is the correct one, half in - half out of the shroud. I've added all the seals that are supposed to help, but they didn't. The thermostat is the correct 180 degree and is also new.

I could buy it from DeWitts, but I'd also have to pay shipping, so Summit Racing is a better deal. (The same price as DeWitts, but free shipping and handling.)

I know the stacked-plate radiator is the best (the one on there now isn't stacked. It has tanks), but I REALLY can't afford a stacked-plate, so I guess I'm just going to have to bite the bullet and get the 1239069M.

Ed

[Joe L.]

Re: DeWitts (Yes, again!)

Thanks guys. I'll admit the DeWitts is a nice radiator, but I'm just afraid that once it's installed I'll have the same issues. I would hate to spend that much money on something that wouldn't resolve the issue.

I've rodded the old one twice in two years (from a local radiator shop), but it still doesn't do the job so I guess it's time to get something else. I think it's just worn out and has lost most of its cooling ability.

Yes, I've taken readings with my IR gun and it actually jibes with the gauge (which is surprising since most gauges aren't that accurate). I've adjusted the timing to help, but even with that, the car still runs very hot when running around town in the heat of the summer. The fan clutch is new and the fan is the correct one, half in - half out of the shroud. I've added all the seals that are supposed to help, but they didn't. The thermostat is the correct 180 degree and is also new.

I could buy it from DeWitts, but I'd also have to pay shipping, so Summit Racing is a better deal. (The same price as DeWitts, but free shipping and handling.)

I know the stacked radiator is the best (the one on there now isn't stacked. It has tanks), so I guess I'm just going to have to bite the bullet and get one.

Ed

Ed-------

The DeWitts Direct Fit has a greater cooling capacity than the stacked plate radiator (GM #3007436). The stacked plate radiator was never used on any big block except L-88, ZL-1, and ZR-2. It was not used with a fan shroud for any of these applications and, thus, there is no GM fan shroud that was ever designed for use with it. If you were to use it, you would also have to change or modify your radiator support.

With the DeWitts Direct Fit you have to change or modify NOTHING. It's a bolt-in replacement for what you have now.

There's another course available to you if you are convinced that your radiator is "worn out". Simply have it re-cored. That way, you use your existing tanks with a brand new core. Thus, you have what is, essentially, a new radiator. I believe that DeWitts sells cores for your radiator but, if not, you should be able to get them in the aftermarket. This will cost quite a bit less than a new Direct Fit and it should cool equal to what your radiator did when the car was brand new.

[Edward B.]

Re: DeWitts (Yes, again!)

Joe, the radiator shop said they could re-core mine for approx. $250-300 (parts and labor), and I thought about that too, but since it's so old I'm leaning toward just replacing the entire thing. It's not an original Harrison radiator (it's an unknown aftermarket that was on the car when I got it), so it's probably not worth spending too much time and money on. And I've already spent more money having it rodded out than I should have!

Ed

[Patrick B.]

Re: DeWitts (Yes, again!)

Ed-------


This is absolutely my radiator of choice for any 1969-72 big block application. It's configuration is very close to original. It has more cooling capacity than any radiator EVER originally installed in a Corvette from 1953 to 2015. In fact, I'm using one in my "ZL-1" application even though I have 2 NOS GM #3019190 and 2 NOS GM #3007436 radiators in my collection [none for sale]. I can't tell you how well it works since I have not run the car yet. However, I'm VERY confident it will work great.

Other than the NOS radiators and DeWitt reproductions of the 3007436, there is absolutely NO other radiator that I would use for a 1969-72 big block. None. Period.

Joe --- You will no trouble cooling a ZL-1. I have had a ZL-1 in my 70 LT-1 car for 33 years using the original LT-1 radiator. It almost never gets over 180 degrees. I had it out 2 days ago and it still runs cool despite the 45 year old small block copper radiator having never been serviced.

[Edward B.]

Re: DeWitts (Yes, again!)

Another question. natural aluminum finish vs. the black painted finish. I don't show my car, so which would be better from a cooling standpoint? Would I gain anything from NOT having it painted? Even if it's just a degree or two?

Ed

[Paul D.]

Re: DeWitts (Yes, again!)

I would have no doubt that the Dewitts replacement would be your best choice for a replacement radiator if the radiator is, in fact, the problem. Since you say the current radiator is not a factory radiator, it may very well be the problem. However, you seem to have some doubts or concerns that it will not completely solve your problem. I would suggest that you search the archives for posts on recurveing your distributor and converting to direct vacuum for the advance. I am assuming the engine is in proper tune and the advance is the best choice and in working order. Also, make sure the fan shroud is properly sealed to the radiator and support. If all of the above are addressed and in good shape and you still have issues, I would then lay out the big bucks for the new radiator. I would not consider re-core on a off brand radiator vs a new DeWitt's to save a couple hundred bucks. Chip.

[Edward B.]

Re: DeWitts (Yes, again!)

I would suggest that you search the archives for posts on recurveing your distributor and converting to direct vacuum for the advance. I am assuming the engine is in proper tune and the advance is the best choice and in working order. Also, make sure the fan shroud is properly sealed to the radiator and support.

Yep. Already been done.

Ed

[Joe L.]

Re: DeWitts (Yes, again!)

Another question. natural aluminum finish vs. the black painted finish. I don't show my car, so which would be better from a cooling standpoint? Would I gain anything from NOT having it painted? Even if it's just a degree or two?

Ed

Ed------


GM never used an aluminum radiator in any 1963-72 Corvette that was not painted black. I believe that tests have been done which demonstrate that there is no loss of cooling efficiency when radiators are painted with radiator-specific paint.

[Edward B.]

Re: DeWitts (Yes, again!)

Thanks again Joe. Black it is.

Ed

[Thomas H.]

Re: DeWitts (Yes, again!)

Ed,

I fought high temperatures in my 71 LS5 for the better part of two summers after I bought the car. Went through everything, IR gun testing (comparing to gauge), timing, shroud, seals, vac adv canister, hoses, had radiator cleaned, pressure tested - twice. Finally bit the bullet and bought a Dewitts. Since I installed it, I have had ZERO issues with engine temperature. As far as I'm concerned, it was the best money I spent on that car - no longer need to worry about temperature when going for a ride. Oh, I installed that radiator about 8 years ago.........

BTW, I put a Dewitts in my 60 and have one ready to go into the 58 I'm working on now.

Tom