With a case with front intake, 1 upper rear exhaust fan, and top used by a cpu. what direction should fans blow for best airflow ?

I thought you said you were running a 360mm radiator, right? So those fans on the radiator would be exhaust fans for sure. Heat rises, and either direction of the fans won't have any real effects on CPU temps just as long as you have the right amount of static pressure forcing it's way through the fins of your radiator.

Since that's the case, the only fan in question here is the upper rear exhaust fan. I have this fan set up as in intake fan for 2 reasons.

-One is to help move cooler air across the VRM/Socket area of my motherboard.

-Provide fresh and cool air to be exhausted through the radiator.

-The case stays cleaner because I have created a positive air pressure environment inside my case. However, I have to make sure the combined CFM of my intake fans is greater than the CFM of my exhaust fans.

I also use a fan to directly cool the VRM. The pressure of the air moving across those VRM heatsinks helps dissipate heat.

greater total cfm should be out. bottom fan slot usually occupied by psu, right, and is out already.

i use a left side fan directly over my gpu and blowing directly on it ..