Yes, the ports are raised, and the intake faces moved in to keep the dimentions in place to use a stock dimension intake, but that lifts the intake higher off of the block. W5s and early W7s were like this and needed the spacers to seal the ends.
There is nothing to stop someone from using these heads on the street, but the ports are larger, and it will kill low end torque. Port velocity will be way down. I drove a race 340 on the street for a while in a Demon back in the 90s. It had no power under 3500 rpm. It was a total pain in the ***. With an automatic with the right converter, it's doable, but still not pleasant in traffic.
Putting a dual plane intake on these heads is just crapping money away, as far as I'm concerned. Buying race parts and then de-tuning the engine is a waste of time and money. Good running engines are about carefully selected combinations. Compromises make performance suffer, quickly. You'd probably be money ahead to stick with RPM heads.
