I'm sure it's been brought up before...but if it hasn't...
In the advancement of HAI technology...why not use a spare heater core with a spare heater/variable valve that's plumbed into the original heater hose circuit with a "T" connector? That way you could actively control how much consistent heat you git through yer intake at any point instead of relying on the heat build up under the hood...
I guess one could argue that yer pulling the heat buildup out under the hood with the intake as well instead of using the heater core...