MAC cold air induction. Should I add MAF or keep stock?
 

I just put MAC cold air kit, x pipe, and catback exhaust on 2000GT. Will an aftermarket MAF help out? I heard the stock one is sufficient for my setup. But I will soon be adding a Diablo chip and 4.10 gears. Anybody have input?

A new Mass Air Meter should give you a few horsepower - from what I have seen the meter helps more than the cold air kit or throttle body and complements these two mods well. You may want to think about Steeda underdrive pulleys and timing adjuster before the MAF as these two mods together cost a little over $300 and give you over 15hp, whereas the mass air would only give you a few.
New gears is an excellent mod and will give you the best seat of the pants results.