How much fluid should be flowing through the steam pipe a slow trickle or a fast steady stream?

 

There should be a decent stream flowing into the radiator at idle.

 

Yes a decent stream is normal but really long as there is more than a dribble it should work fine as it is really to purge air and steam bubbles, doesn't need to flow a lot of liquid to accomplish that.

 

The factory must expect it fo flow... in 95 they routed that line through the throttle body before sending it to the air separator in the radiator. I have a second coolant temp sensor in the steam line before it dumps into the radiator, and it reads the same as the sensor in the head.