I've had an aftermarket aluminum radiator in my '68 Cutlass for years, and it recently began leaking. I looked at radiator prices and was surprised (what, prices have gone up in the past 20 years? lol), but in the end ordered a Dewitt direct fit radiator. When going to install I noticed that the top plate is interfering w/ the fill spout, even before the cap is installed. This w/ the radiator pushed hard against and nearly flattening the passenger side rubber seal in the core support. On the driver side the top plate isn't even on the tank. I'm sure I can modify the top plate to make it work, but am wondering if there is something obviously wrong (wrong top plate, modified top plate, etc...). I'm stumped - Dewitt has a good reputation so I'm assuming their part is correct. For what it's worth the old generic aluminum radiator fit fine.

 

I thought the tank seams should fit into the rubber saddle insulators. ??? The one on the drivers side looks to be too far left.

 

I had to rotate the image because it was hurting my brain...

 

Since there was an aftermarket aluminum radiator installed in the car for numerous years (evidently not by you) anything is suspect I suppose i.e. not the 1968 OEM upper support, but instead an upper support which was able to accommodate the aftermarket aluminum radiator. Is there a difference in dimensions between the Dewitt and the aftermarket which was in there? I'd certainly start with an exact measurement and compare the two especially relative to the saddle locations.

 

That's an incorrect top plate that's been modified previously.

An original 1968 top plate for a two-row or three-row radiator looks like this.





The top plate for a four row radiator looks like this.

 

I just looked at mine and confirmed the end tank seams sit in the rubber isolators. The edge of the drivers side inlet is below the edge of the top plate.

 

Thanks for the assist guys. I can start by trying to find the correct top plate for a 68 and see if that changes anything. I'm guessing the top plate is from my '70 Cutlass, which is where the radiator also came from.

There is a difference in the end tank sizes. The overall width of the radiator is the same as the aftermarket I had in, but the aftermarket had 2.5" wide tanks on both the DS and PS sides, whereas the new radiator has 2.5" PS and 1.5" DS. That would explain why the DS side top plate saddle doesn't reach the tank, but wouldn't explain why the PS side is interfering w/ the filler spout. The other difference is the aftermarket radiator fill spout was at much more of an angle from horizontal, while the new one is nearly horizontal. Hopefully it is all magically addressed by the correct '68 top plate.