I replaced my plenum gasket and intake gaskets yesterday and wow does my truck have a lot more power, it idles smoother and acceleration is snappier and i think i will get better gas mileage. also it runs better on cold starts after sitting overnight.no blue smoke or rough idle. fixed my spark knock issue at 2200 rpm. also as a tip. the inside of my intake, throttle body and plenum looks like brand new. so clean i can eat off it. i tried carb cleaner to clean it and it as still dirty, so i sprayed it down with oven cleaner and voila it looked like new. some parts require a tooth brush to scrub but now if i ever have a bad plenum gasket i can tell instantly by looking inside since it is spotless clean now. i was surprised the difference it made being the engine only had 80,000 miles and that plenum was definitely leaking.

 

Just remember that with great power comes great responsibility.