This topic has been discussed many times. 100's of guys have found that an aluminum aftermarket intake may need water heating full time to run properly at lowers speeds. The typical complaint is hesitation due to lack of fuel vaporization because of a cold intake manifold.The aluminum doesn't retain heat like cast iron.
If you have a proper functioning heat riser on a stock cast iron intake, try and place you hand on the intake just below the carb after a half hour. The darn intake is hotter than hell despite the heat riser being fully open.it might even be hotter than a water heated intake..
