[rexs73gto]

That may have been the case with the Alum. 4 core but I had a 4 core from the factory in my 73 GTO. My 73 GTO came from the factory with a 4 core & since new it NEVER would over heat or run hot. I know as I bought my car new & put all the miles on it myself. It always ran right at about 180* no mater if I let it sit idling or running it hard on the track or street. I put that 1st Alum. in & it ran a bit hotter at first but came to run at the 180* mark after that. After the engine got broke in , because when I put the new rad in I had rebuilt the engine. Now after the 2nd year when I brought it out for the summer season after sitting for about 7 mounts it seemed to run a bit hotter & then hotter & then finally it would overheat if I got into traffic or in slower traffic. I couldn't let it sit for more then just a few min's without it going into boiling temps. Now with this new one & it look to be a great rad. as the welds are very good & the tanks seem to be very thick. I cost only a little & I hope it holds up, but if not I can buy another for the cost of 1 of the last one & I bought that 7 years ago. SO.... Maybe it was just to thick but it is all good now & I thank the new rad. for that.