So where are you guys running the hose coming off the steam pipes? Can it be tee'd into the overflow bottle hose coming off the cap? Or what about an adapter to tee it into one of the heater hoses?

 

I am having the same issue but i rebuild my motor, one thing i seen is the head gasket you use,.

If you look up the head gasket part on your make and model some will have a block off on the front where the crossover pipes are and the back is always flowing idk if running a line to one head to the other will lose pressure for the front two or not
i have put after market Cross over pipes on 243 heads that leak no matter what I do , they where heads from ebay i ordered snd port and polished is there any way to fix it leaking there after it gets hot and builds pressure thank you