Spending money elsewhere would be better if the intake is stock. As for the spacer, if you are talking about the EGR plate then yes it has to be changed to the diameter of the T/B.
if you going to a 65mm throttle body you without the change of heads, cam, or intake manifold you will not feel much of anything if anything. i suggest you save up for a good h/c/i. or do something simple like gears or pulleys if you have not done so already. you can buy a bbk, mac, or ford racing egr plate aftermarket in 65mm. the ford racing one will actually be 67mm.
For the money with stock intake/heads etc, a mass air meter is the best, that of course you don't have gears yet. Search the classifieds, you can find a C&L cheap.