/6 Hooker Headers...surprise

Intake manifold heat is commonly misunderstood to be just a cold-weather thing. It is not. Read this (and watch the linked movie) and this.

(Unless you like sending raw gas and the money you paid for it out the tailpipe and down the cylinders into the crankcase to crap up and dilute your oil…in that case, go ahead and run without intake manifold heat.)