My picture shows the early hot idle compensator (without wings), the later HOC with wings, and the "dummy" HOC, no compensator, just wings.
First question - yes.
The deflector cost about 35 SECONDARY CFM or approximately 6 percent airflow. The beauty of this modification is that only WOT maximum RPM is effected. Up to maximum RPM, the engine was running to its peak performance. The maximum RPM was reduced slightly. Check power ratings for 4-barrel and tripower engines 1964~1966 and you will find the tripower is rated at slightly higher HP at maybe 200 higher RPM. Now you know the rest of the story.
Second question - no.
The hot idle compensator without the "wings" was used on many other applications with automatic transmissions, including earlier Pontiac, and in fact, worked well.
The hot idle compensator with the "wings" was used on Pontiac 1964~1966 with automatic transmission.
The "dummy" hot idle compensator (no compensator, just the "wings") with "wings" was used on Pontiac 1964~1966 with standard transmissions.
As a general rule, hot idle compensation was not used with standard transmissions.
So - to improve performance on automatic transmissioned cars, replace the winged HOC with the non-winged HOC.
To improve performance on the standard transmissioned cars, just remove the dummy. The HOC passage is not machined on the standard transmissioned carbs.
Later, Pontiac pulled a similiar trick (limited butterfly movement) with Q-Jets on Firebirds, so the 10 pounds / HP formula was not violated.
Marketing departments played games.
Maybe a better example (certainly one more widely known) of marketing games (much later) was tire shaving for cars used in magazine tests (and Chevrolet got caught
). Look for a "Road & Track" article in the 1980's (I think) entitled "Can we build one for you?"
Jon
