I finally broke down and decided to buy an aluminum radiator for my 77 l-48. I tried everything from flushing to electric fans, sealing around the radiator and even extending the front spoiler. All of these efforts had an effect just not enough to satisfy me. I wanted an engine that could run at the thermostat while doing 75 down the highway. The best I could do with original radiator was about 195 or so on warm days with the A/C off.
The electric fans had a dramatic effect at slow speeds but at highway speeds it still got hotter than I wanted, as high as 220 to 225 on hot days with A/C on.
The extension of the spoiler lowered the temp about 20* on average on 90ish days. So instead of 240 I would see maybe 220.
Still I wanted more. If I am going to increase the HP of this engine then I am also going to increase the heat it produces.
I looked at and considered many different aluminum radiators but in the end decided that doing it once and having a good fit were priorities in this case.
So I bought this radiator;
http://www.zip-corvette.com/ProductD...GR-SR&CTitle=&

Just got it installed yesterday. The fit was perfect. I don't mean it was close, it was perfect! Amazing to me that this is a product that lives up to it's hype. Bravo Mr. Dewitt! I even have a oil cooler between my A/C condenser and the radiator and this new radiator did not interfere with that at all. The new rad also came with the appropriate replacement rubber mounts top and bottom.
The cooling of this new rad is nothing short of astonishing. My temp gauge starts at 100* for the first mark and 200* for the mark straight up on the gauge. In between is a mark half way. So I guess that would represent 150*. The entire time I drove the car at 75 to 80 MPH the gauge did not budge from what appeared to be 175*. Which is about right since I have a 180* thermostat installed. Nothing I did in the past ever saw a running temp this cool.
On the radiator I have a radiator cap with a temp gauge in it and when the inside gauge read 175* the gauge on the radiator read 130*. Previously the radiator cap would read 180*-200* with the interior gauge reading of 200* to 220*.
So Thank you very much Zips and Dewitts for a quality product.

 

I agree 100% about the Dewitts radiator!!!! I chased my problem since 1983 on my L-82 4 speed and did EVERYTHING to address the car getting very hot on the highway issue-it's the smog heads that cause the problem on the later C3's. Finally broke down and purchased a Dewitts radiator along with a Stewart Stage 2 aluminum water pump. 175-180 degrees now on the highway at 80 MPH-first time in the car's life the temp was normal!!! Normally operating temp when the car was new with all emissions hardware was 225 degrees on cooler days and 240-245 on hot days with the A/C on running on the HIGHWAY!!!

 

my 79 L-82 runs 160 all the time always has since the factory timing settings and carb jetting was changed. plus the 160 thermostat. i will likely install a dewitts at some point.

 

On behalf of Zip and DeWitts, we thank you for the support

 

Right on!!!! I love my Dewitts radiator. The car has never run cooler, and, it was a perfect fit. Great product!

 

Nice to hear in a similar boat myself (saving for a good one)

whered you get the cap with the temp deal in it?

 

Got it off of e-bay.
http://www.ebay.com/itm/Camaro-Trans...5d9d53&vxp=mtr
If you look around you may be able to get it cheaper or at least free shipping. It is accurate. I verified it many times with an IR temp gun.

Thank you Tom. I find it rare for a product to live up to it's reputation often. This radiator certainly does. I have ordered a few things from Zips and have always been pleased with the service. They will probably get a lot of my business in the future.

 

Don't bother with anything else...install a Dewitt's radiator and know that you have the best possible cooling available anywhere....

 

 

Agree, Dewitts the way go.
Another satisfied customer.

 

 

I bought a Dewitt at the recommendation of members on here back in the spring. When it came it the outlet pipe at the bottom had an interference issue - I called Dewitts and sent them pictures and they had the bad unit picked up and sent me a new one promptly and were very apologetic for the issue - the replacement one fit perfectly. I was also impressed with the quality of the radiator.

If only every manufacturer took their same approach to customer service!!

I am a VERY happy customer of theirs, they are top notch in my book!

 

This doesn't have a temp gauge in it but it does look really cool

 

Where can I get one for my 72?

 

I am also a VERY SATISFIED Dewitt's customer!!!! Got the aluminum radiator with dual Spals, vette has never run cooler!