that silver one looks like it's ready to roll. take care of it, and you'll be able to sell it, for what you paid for it.

as far as throttle body spacers not working, i'll refer you to the testing done on all motor mods, by 4 wheeler network. they have done real world testing on a large collection of "power mods" for the 4.0. i'm not sure why it works with mpfi systems, but it does offer some gains. maybe the added plenum volume allows for less turbulence? maybe the motor just think the thing looks cool, so it tries harder? who knows.

4.0 motor mods test