goin' custom

[98xlt]

Hello all, i've had an evo for a few years now on lvl 3 but fordf150.net has me convinced i need a cs. A few questions before proceeding - Does an intake spacer affect a custom tune at all or should i just keep that waste of money as my little secret? Also, as far as future mods, i had read that a larger TB may decrease low rpm performance. Don't know if a larger MAF works similarly. Is this true, and do custom tunes correct this to make gains? Thanks for any input.