The trap of the industrial / motorhome 318-3

these are the 234 heads I've mentioned before that a lot of people on here didn't believe existed wiith the blind exhaust ports, *no more flow loss due to the exh cross over*

A '67 only head.

And you can block the water cross over...

Are you talking about the heads on the engine in Del's photo? What exhaust did you run? The industrial/motorhome heads have a different dedicated exhaust bolt pattern