One final note on our test engine. The small-block Edelbrock Performer RPM intake has proven to be a true winner on the LA engine. Unlike the big-block version, this dual-plane intake uses a full plenum divider to the carb base. An interesting question is whether cutting the divider down by 1/2-inch or so would give some of the added performance the open spacer offered. This picture shows the layout for our baseline, a 1/8-inch steel spacer and two gaskets.