I run the 234 heads on a 318, just plate off the water cross over with rtv and a thin peice of metal like you would if it was an exh cross over.
Look... for those who don't know, the only advantage to these heads is there is no exhaust cross over meaning all the exhaust ports are blind. When you have a port in each head that is open on the far side of the bowl to feed a cross over...the exhaust goes the wrong direction....get it yet? No more 1 out of 4 ports flowing less than the other 3.