I read about that rad upgrade but that was posted a long time ago, they sell 1 1/4 listed for grand prix now...

the extra 1/8 is not much of a concern for me, its only a GT but has 360,000 km, would like to keep it nice and cool from now on

I ordered the 1 1/4 from rock auto, they sent me a 5/8 by mistake.. they said just keep it and they will send me the 1 1/4 sorry for the mistake

I guess i have an extra rad?

Is it a good idea to replace the hoses as well ?