Econo heads have the rocker stands cast into the head.
There are two versions of econo heads.
One that take the same length valves as normal SB heads, and one that uses the same length valves as the non-econo heads.
The ports on all of those versions are the same, when they are all of the same vintage.
The “econo” part was referring to the cost of the rocker gear.
Econo:
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Non-econo:
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