I replaced my heater core three times. First one does not OEM it was not a rectangle. Second one didn't fit as well. Had to go with OEM heater core. It still was a pain in the you-know-what. That I came with up with an idea. I used a C-clamp for a third hand and it worked like a charm. Very gently that is. Especially on the top pipe. Wrapped a little electrical tape to protect the pipe then put a clamp on it. Then I used the C-clamp which was 5 in and work like a charm.

 

We use these OEM ones and have never had any fitment issues.
https://www.waymotorworks.com/heater...0-r52-r53.html

 

right on. Glad to hear that I wish I would have known I would have probably have saved money.

 

After 2 attempts of ordering online I had to wait while my car was down. Figured it was easier just to go to the dealer and see it and touch it to make sure it was right. I won't mention who I ordered it from the two previous times but it definitely wasn't you guys