Just did this on my truck and will advance timing a couple degrees to use it to max benefit... Remove (or cut) the heater lines into and from the intake, so it runs at ambient instead of whatever temp your vehicle is running, REALLY noticeable on cool crisp days (or cold even better)! I cut the small 90 degree one from t'stat first, then the one up from the heater into cab fitting, plugged both, and voila, def a bit more pep after warming the fluids up...! Good for bang/buck ratio!