You can not feel a difference bolting on just a set of EQs, been there done that. You can feel the extra TQ down low with a good cam like the one mentioned. A bigger TB by it self you can not feel. All together would be real nice and help all through the RPM range.

In my experience with these magnum engines a good cam (short duration high lift and a little tighter LSA) is the best thing you can do for low RPM.

As for a cold air intake, how can it do much when the air is baked after it goes through the air tube on the plenum pan? Keeping the hot oil off the bottom of the intake reduces air temp and increases density as it flows through the ports/valves. I think the biggest reason the hughes air-gap intake makes such a difference is the air-gap not the runner shapes/lengths. When it was -20 degrees this winter my IAT was reading manifold air temps well over 100 degrees during steady cruise. How the heck can air that hot make any power? Adding a K&N CAI did almost nothing for IAT at those frigid temps. This is what lead me to try the extra plenum plate with a space between them.

PS if you pull the heads put on some of the thin mr-gasket head gaskets for a small compression bump.