I think all modern automobiles have some heat source applied to prevent icing of the throttle in wide open condition in cooler -- below 70 -- damp -- high relative humidity -- situations. The radiator line I put a shut off valve on is a 3/8" line from the radiator to throttle body not main radiator line to engine block. I checked today with valve open after using car for 30 minutes that top of throttle body was warm maybe 135. When weather warms up a little more I will shut off valve and see how warm throttle body appears when engine is hot. I read on internet someone with Firebird, exact same engine, slightly different throttle body gaining 9 HP backed up with dyno results. My mid life crisis is not harming anyone except for a little more CO2 produced. <g>