Depends on the tune. Anywhere from stock to maaaaybe +15 or 20 depending on how good the tune was.
Ditch the TB spacer.
2002 C5 Z51. MCS 2WNR TT2 coilovers, 18x11 Forgestars, 315's, yada yada. Built Z06 T56. Bolt ons. Coming soon to a CAM event near you.
2013 F150 6.2L. 9mpg.