Ok, you all have probably heard of my 2 fieros to 1 project by now. I kept the radiator out of the 6 cylinder car, because I have heard that they are a 2 core where the 4 cylinder radiators are only 1 core. How do I tell the difference? I thought to look down into the filler cap hole and count the horizontal fin tubes. Is this right? I think they are both 1 core radiators. thanks for any help in advance.

Actually both of those radiators are ONE core. The 6 cylinder Radiator just has a little bit wider core.

Here is a picc. of (from left to right) the 4 cyl. rad., the 6 cyl. rad & the 4 core radiator that I have custom made for the Fiero.

The 4 cyl. Rad. is just less than 1" wide
The 6 cyl. Rad. is almost 1-3/8" wide
The 8 cyl. Rad. is just over 2-1/8" wide

I've never cut one apart but you can look into the rad. cap opening and see the cores.

Hope this helps.

Archie