The very first thing I would do is get a cylinder compression test. This will help you locate which head has the problem or if you even need head gaskets. Since you have had a complete engine replace. It's possible that you could have a leak in one of the many hoses. The engine does not have to be removed to replace the head gaskets. It would be best to replace both if you need to replace one.

Here's a link to the service manual at Infinitihelp.com you'll have to register but you can download the Engine Mechanical Section which should contain the Cylinder Head info for free. http://x.infinitihelp.com/forum/loca...s.php?catid=20

 

Thanks for your help I brought the car back to the shop and they are the ones that told me my driver side headgasket is leaking not alot but def leaking. I get a really strong coolant smell on cold starts and always a hint of coolant from the exhaust. I'd there anything else I should consider while I tackle this? Not going to do it till spring so I have alot of time to read up. Is it worth modifying the heads since they have to come off anyways?