Ok so I just put a ls intake mani on my b20z2 swap. Now it's overheating, it gets half way up the temp gauge and slowly keeps moving but the fan isn't kicking on?

Also there was a diff in the mani's. The old B20 mani had 1 port for coolant, now the ls has 2. I runs to the fitv (which I already have one coming from the thermo housing to there) and the other is on the back of the block where the lower rad. hose runs out (but that was there on the other.)

It's running great besides this. Any thoughts? No cel's and it is trying to push coolant out the port that I told you the ls has but not the b20. But at the same time it is pushing coolant from the front hose coming off the thermo housing.

 

Just thought I would add this. The return hose from the back of the block is cold. Thermostat not opening?