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Important! Aftermarket Radiators- What to Watch For


Mar 2, 2002
Dark Blue 1982 Trans Am(s): Polo Green 1995 MN6
I recently replaced my radiator on the '82. I had replaced the radiator on my '80 and in both cars I went with aluminum.

A lot of folks will say go with DeWitts and be done with it... that may not meet your needs for cost, size, etc. You can find other radiators and they will fit- but here are a list of things you need to consider...

Things to watch for:
  • Width, height, and depth: I think this one goes without saying... make sure your radiator fits!
    [*=1]Depth: There is a little room front to back- and if you are willing to remove or find smaller foam cushions that go between the radiator and the core support you are okay. For the depth- I'd only go 1/8 of an inch larger over OE.
    [*=1]Width: For the width, you may actually have more you can work with there. I'd only consider 1/4 to 1/2 inch wider than stock. TIP: KEEP YOUR EYES ON THE TOP BRACKETS AND CUSHIONS. You will likely need to modify the cushions (remove material) if you go with a wider or deeper radiator.
    [*=1]Height: This is one that I would NOT deviate from. You need to go with the stock height unless you really want to modify the removable top brackets on each side.
  • Rows & Core: Make sure this is done right. I won't go into details, but all welded is better than epoxy. Two wide rows are better than three small rows with excess solder or epoxy mess that reduces the flow. You want to go with well constructed core. Otherwise, you'll have an expensive mistake on your hands!
  • Lower Hose inlet angle: This is critical for the C3. OEM points up almost 80 degrees or so. If you find a radiator with a lower pitch, you will need to find a hose that fits- and the OEM hose won't work in that case. You will likely need a flexible metal hose or a universal corrugated rubber hose from the parts store.
  • Stamping or machining for the cap/filler neck: This is the most critical part- if the stamping or machining isn't right there's not much you can do. I have personally seen poor machining jobs that have made it almost impossible to get a cap on. CHECK THIS FIRST!!! If you can't get a cap on it easily... SEND IT BACK! You can deal with most other challenges- but getting a cap on it is non-negotiable. That is a must have!
  • Automatic Transmission lines:These may screw in either higher or lower relative to OE. Likely the bottom line will be close to OE but the upper line can be as much as an inch higher than OE. When you have the radiator out- it is a good time to replace the sections of rubber line. TIP: When you re-intsall the cooler lines, disconnect the rubber lines from them so you don't accidentally cross thread the metal flares when you bolt it back together.

For my '80, I found reasonably priced 2 row core. It was an Ebay radiator and it was actually constructed very well and fit perfectly with NO modifications at all. It was also about $250. It was slightly wider than OE but the height and depth were the same.

For my 82, I tried a "direct fit" radiator from a well known company and was less than impressed. When I couldn't get a cap on it due to poor machining, back in the box it went.

Ultimately, I went with a DeWitts. I would personally recommend DeWitts for anyone who doesn't want to mess with measurements or trade-offs. Again, you can find a good aftermarket radiator for less... but you need to be on the ball in terms of all the things I mentioned above.

I had a problem with my replacement radiator when I put it in...
the upper radiator hose was a different size than my OEM,and as a result,
I ended up getting a custom fit radiator hose,what a PIA!!!!!:mad

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