OK, since I have a std, I have answers with experience.

The upper plate does help throttle response, but it also limits overall flow, remove it, by taking out the 2 screws and reset the ecu.

Also, if you look at the IM, between it and the tb setup is a small black plastic plate. This is an air restrictor plate, remove the plate or bore it out because the stock std plate reduces the intake passage to 35mm down from the normal 47mm size. With the Dx cam, manifold, the plate removed, and the upper flipper, you'll be as fast as or faster than a DX. wooohooo!!

You don't need the dx rockers though, just put the dx cam in and do a valve adjustment. Better yet, buy a Si cam and you'll be much happier, Personally I wouldn't even spend the time putting the Dx cam in. 1/2-3/4 hp at most... the manifolds have the main difference.