If I told ya to jump off a bridge at low tide but is was not a good idea would ya still jump ? I have to guess so.
Just trying to emphasize the point that cold air adds HP, if ya can't read that your probably still looking for that can of striped paint, I would say a L/H shifter but they really do exist, I have a L/H 15" gedore shifter (the adjuster closes when turned back towards you, opposite from the 99% of all others), unfortunately the best anyone can ask for is ambient air temp at the t/b, that alone is near impossible unless some good CAI setup is made which actually allows ambient air at the t/b.
Why do many exotic V8 cars like corvettes and the likes suck air from bonnet vents ? geez I would assume that any Australian has seen the A9X torana which had a huge bonnet scoop that actually opened up to the carby, it's was not there for looks, perhaps the point is obvious, that very tiny slot of the stock forward facing CAI between the bonnet and front apron is really doing stuff all, I mean taka a look, the gap there is under 10mm, not a huge scoop by any means.
Most have seen the underhood of any V8 supercar and must figure that ya can't see the engine for the huge air box (without a filter) which draws outside air from in front of the windscreen, a high pressure area, where does your stock vent draw air from ?? you figure, it ain't from the front of the car, only thing cooled at the front is radiator, engine, gearbox, brakes, the engine would shat itself rather quickly after any gutfull of sand trap gravel.
The old red motors were simple to do, Black motor commos do the same, merely cut off the forward facing snorkel from the air filter housing, turn it around so the opening is pointing to the firewall and pipe it through the firewall and into the air duct section, bingo CAI that costs stuff all, and works a treat, where do ya think my old kingswood /500 holley used to suck from ? that is guaranteed to work.
This fetish for chasing tiny amounts of "maybe" HP is realy a waste of time and money, unless your prepared to do it properly leave the inlet alone and bung on some good headers and a decent exhaust and change the chip, at least then you will feel a difference in HP.
Been there done this many times, and it remains the same, either do it seriously or don't bother, go fishing instaed, at least a heat sheild must be installed between the headers and inlet, at best insulate the entire inlet system with a forward facing duct in front of the radiator, if done properly it will look and work properly, copy off some race cars ?