yes be sure that that little o-ring gasket is still there... when i was putting my motor back in (22r) that little gasket was missing and it caused the intake area to leak coolant as well. the o-ring gasket can be had from toyota for 2 or 3 bucks.

i dont remember that coolant line that leads from the intake around the back of the motor having any welds in it, the onle on my 22r is all one peice with no welds.

It's the one connected to the intake under the temp sensor going to the bypass for the heater on the firewall

yeah there is a little o-ring that goes in between the hose and the intake. when i put mine back together without it, it leaked pretty bad, got a new one at toyota and it cured the problem.